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Endocrine mcq

pediatric MCQ on endocrine branch

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Endocrine mcq

  1. 1. ENDOCRINE MCQ ABDULRAHMAN BASHIRE
  2. 2. ‫اھﺪاء‬ ‫ﯾﻧﺎل‬ ‫ان‬ ‫ﷲ‬ ‫ﻣن‬ ‫راﺟﯾﺎ‬ ‫اﻻطﻔﺎل‬ ‫اطﺑﺎء‬ ‫ﺟﻣﯾﻊ‬ ‫اﻟﻰ‬ ‫اﻟﻌﻣل‬ ‫ھذا‬ ‫اﻗدم‬ ‫ورﺿﺎﺋﮭم‬ ‫اﻋﺟﺎﺑﮭم‬،‫واﻟﻣﻐﻔرة‬ ‫ﺑﺎﻟرﺣﻣﺔ‬ ‫اﻟدﻋﺎء‬ ‫اﻻ‬ ‫وﻻاطﻠب‬ ‫روﺣﻰ‬ ‫وﺗؤام‬ ‫وﻋﺿدى‬ ‫ﻻﺧﻰ‬"‫اﺣﻣد‬".‫ﻟﮫ‬ ‫اﻏﻔر‬ ‫اﻟﻠﮭم‬ ‫ﺟﻧﺎﻧك‬ ‫ﻓﺳﯾﺢ‬ ‫واﺳﻛﻧﺔ‬ ‫وارﺣﻣﺔ‬. ‫اﻣﯾن‬ Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)
  3. 3. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 1 22/12/2017 1. The plasma ionized calcium level is increased by: A. Parathyroid hormone. B. Acidosis. C. Hypoalbuminaemia. D. Massive blood transfusion. E. Calcitonin Ans:-ABC 99% of calcium is found in bone. Of the remainder, 50% is bound to plasma proteins and 50% is ionised. Parathyroid hormone causes mobilisation of bone calcium and increased renal calcium absorption. Calcitonin inhibits bone mobilisation of calcium. The ionised calcium increases with acidosis and decreases with alkalosis, and for accurate measurement of plasma calcium a tourniquet should not be used. Plasma calcium should be corrected for the plasma protein level by adding 0.2 mmol/l calcium for each g/l albumin below 40 g/l. 2. With regard to bone metabolism ; A. PTH and calcitonoin genes are located on chromosome 10 B. in response to hypocalcemia PTH has an immediate effect on intestinal absorption C. Vitamine D dependent rickets type 2 is caused by deficiency of 1ά hydroxylation of 25(OH)Vit D D. bone disease of prematurity is caused by vitamin D deficiency E. peak bone mass may be positively influenced by obesity Ans ; E PTH and calcitonoin genes are located on the short arm of chromosome 11, the primary function of PTH is to prevent hypocalcemia , the immediate effect of an increase in PTH is increased Ca absorption and increased PO4 excretion in the kidney alongside osteoclastic bone resorption , the GIT effect is delayed by 1-2 days and occur via increase synthesis of 1,25 (OH) vitamin D . Vitamine D dependent rickets is rare cause of rickets. Type 1 is secondary to deficiency of 1ά hydroxylation of 25 hydroxyvitamine D Type 2 is due to resistance of 1,25 (OH) vitamin D . both are treated with calcitriol, large dose are necessary in type 2 ,Vitamine D deficient rickets is treated with vitamin D , Hypophophatemic rickets is treated with frequent dose of phosphate & calcitriol as there is associated deficiency of 1ά hydroxylation of 25 hydroxyvitamine D . Bone disease of prematurity is thought to be predominantly caused by PO4 and / or Ca deficiency. and is treated with PO4 & Ca supplements . Brachydactyly is feature of Pseudohypoparathyroidism 2. The following conditions occur due to the presence of circulating antibodies: A. Graves disease. B. Hashimoto thyroiditis. C. Reidel's thyroiditis. D. Myasthenia gravis. E. Motor neurone disease. Ans:-ABD
  4. 4. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 2 22/12/2017 Reidel's thyroiditis is probably viral in origin. In myasthenia, there are circulating antibodies against acetylcholine receptors at the neuromuscular junction. The aetiology of motor neurone disease is not clear. 3. Calcitonin: A. is a polypeptide hormone. B. is secreted by the thyroid epithelial cells. C. secretion is increased by a fall in serum calcium concentration. D. inhibits bone resorption. E. secreted in excess in patients with medullary carcinoma of the thyroid. Ans:-ADE Comments: Cacitonin is a peptide hormone released from the C cells of the thyroid in response to hypercalcaemia. It's hypocalcaemic effects are mediated by preventing bone resorption by osteoclasts. 4. Regarding parathyroid hormone: A. It is composed of 84 amino acids. B. Because of the high circulating serum levels, it can be detected by radio-immunoassay techniques. C. Production is increased by a drop in serum phosphate. D. PTH stimulates activity of 1-alpha hydroxylase in the kidney. E. In pseudohypopararthyroidism, brachydactyly may be present. Ans:-ADE Parathyroid hormone is an 84 amino acid chain protein produced by the parathyroid gland. The first 34 amino acid enterminal fragment possesses biological activity. Hypocalcaemia stimulates PTH production. This stimulates activity of 1-a-hydroxy in the kidney, and enhances the production of 1, 25 di(OH)2D3. The latter induces synthesis of a calcium binding protein (calbindin-D) in the intestinal mucosa with resultant absorption of calcium. PTH also mobilises calcium by directly enhancing bone resorption (with Vitamin D3). In the kidney it is a potent stimulus to the reabsorption of calcium in the loop of Henle. The effects of PTH on bone and kidney are mediated through specific membrane receptors. 5. A 4-year-old child has mental retardation, shortness of stature, brachydactyly (especially of the fourth and fifth digits), and obesity with round facies and short neck. The child is followed by an ophthalmologist for subcapsular cataracts, and has previously been noted to have cutaneous and subcutaneous calcifications, as well as perivascular calcifications of the basal ganglia. This patient is most likely to have which of the following features? A. Hypercalcemia. B. Hypophosphatemia. C. Elevated concentrations of parathyroid hormone. D. Advanced height age. E. Decreased bone density, particularly in the skull Ans:-C The patient with the features listed likely has pseudohypoparathyroidism (Albright hereditary osteodystrophy). Such patients have chemical findings of hypoparathyroidism (low calcium, high phosphorus), but parathyroid hormone levels are high, indicating resistance to the action of this hormone. Parathyroid hormone infusion does not produce a phosphaturic response. Phenotypically,
  5. 5. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 3 22/12/2017 these patients demonstrate shortness of stature with delayed bone age, mental retardation, increased bone density throughout the body (especially evident in the skull), brachydactyly (especially of the fourth and fifth digits), obesity with round facies and short neck, subcapsular cataracts, cutaneous and subcutaneous calcifications, and perivascular calcifications of the basal ganglia. 6. A 12-month-old Asian boy with general ill health and who is clinically anaemic has the following results: Calcium = 2.1 mmol/l (normal: 2-2.5 mmol/l) Phosphate= 0.94 mmol/l (normal: 1.45-1.78 mmol/l) ALP = 1013 IU/I (normal: 30-350 IU/I) PTH = 199 pg/ml (normal: 15-65 pg/ml) A. Hypoparathyroidism. B. Hyperparathyroidism. C. Pseudohypoparathyroidism. D. Vitamine D deficiency. E. Hypocalcaemia Ans:-D Typical biochemical changes of vitamin D deficiency include low/normal calcium with low phosphate, high ALP and PTH, and low vitamin D levels. The main source of vitamin D is UV radiation on the skin. There is no radiation of appropriate wavelength in Britain from the end of October to the end of March. Furthermore, increased skin pigmentation reduces the capacity of skin to synthesise vitamin D. Over the past few years there has been growing concern about the resurgence of rickets in British Asian children and recent immigrants to the UK. This reflects the general decrease in use of vitamin supplements over the years. Other causes of vitamin D deficiency should be considered, such as malabsorption syndrome, chronic hepatic and renal failure. 7. One month old boy present to his local A&E department with generalised convulsions. He has the following result:- Calcium= 1.0 mmol/l (normal: 2-2.5 mmol/l) Phosphate = 2.76 mmol/l (normal: 1.45-1.78 mmol/l) ALP = 349 IU/I (normal: 30-350 IU/I) PTH = 174 pg/ml (normal: 15-65 pg/ml) A. Hypoparathyroidism. B. Hyperparathyroidism. C. Pseudohypoparathyroidism. D. Vitamine D deficiency. E. Hypocalcaemia. Ans:-C This is due to a genetic defect in the receptor for PTH. As a result the biochemical picture is similar to that of hypoparathyroidism, with low calcium, high phosphate and normal ALP, but the PTH is high in pseudohypoparathyroidism. The low calcium is responsible for the convulsions. Classically, these individuals are short, with learning
  6. 6. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 4 22/12/2017 difficulties, lenticular cataracts and shortening of the metacarpals of the fourth and fifth digits. Calcification of the basal ganglia may be found. A 9 month old boy present with fracturedradius and ulna after and ulna after a trivial fall. The radiologist comments on the decreased mineralization of bone he has the following results: A. Hypoparathyroidism. B. Hyperparathyroidism. C. Pseudohypoparathyroidism. D. Vitamine D resistant rickets. E. Hypocalcaemia Ans:-D This is a rare condition characterised by hypophosphataemia, normocalcaemia, and normal or low levels of vitamin D. It is also known as X-linked hypophosphataemic rickets as it is an X-linked dominant disorder and so can affect both males and females. It is attributed to renal phosphate wasting due to a renal tubular defect in phosphate transport and possibly, impaired intestinal absorption of calcium. In some cases there is calcification of the inter-spinal ligaments. Treatment is with oral phosphate and vitamin D. 8. A 14 month old child is found to have a serum Ca concentration of 2.0 mmol/L- phosphate of 0.68 mmol/L- and alkaline phosphatase of 570. Which of the following conditions could explain these findings? A. Pseudohypoparathyroidism. B. Coeliac disease. C. Hypophosphatasia. D. Nutritional rickets. E. Renal failure Ans:-BD Causes of hypocalcaemia are: • Parathyroid hormone deficiency: a) aplasia or hypoplasia, e.g. Catch 22 Syndrome. b) PTH gene mutations or receptor defects (latter includes pseudohyperparathyroidism). c) Autoimmune disease. d) Infiltrations. • Vitamin D deficiency. • Magnesium deficiency - primary hypomagnesaemia, renal tubular defects, aminoglycoside therapy. • Phosphate excess: laxatives. Hypophosphotasia is a defect due to decreased alkaline phosphatase activity. Renal failure usually results in a rise in phosphate, because of secondary hyperparathyroidism. 9. one day old infant presented with convulsion , serum Ca= 6 mg , the least likely cause ; A. high phosphate intake B. maternal hyperparathyroidism C. prematurity
  7. 7. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 5 22/12/2017 D. birth asphyxia Ans; A 10. The presenting feature of psudhypoparathyroidism are ; A. due to defect in receptors at the target organ B. with high serum level of parathormone C. hypercalcemia D. mental retardation E. absent thumbs Ans ; ABD in pseudohypoparathyroidism (PHP), the parathyroid glands are normal or hyper plastic and they can synthesize and secrete parathyroid hormone (PTH). Type IA. accounts for the majority of patients with PHP. Affected patients have a genetic defect of the a subunit of the stimulatory guanine nucleotide-binding protein (Gsa ). This coupling factor is required for PTH bound to cell surface receptors to activate cyclic adenosine monophosphate (AMP) The defect is inherited as an autosomal dominant trait, and the paucity of father-to-son transmissions is thought to be due to decreased fertility in males. Tetany is often the presenting sign. Brachydactyly with dimpling of the dorsum of the hand is usually present. The 2nd metacarpal is involved least often. As a result, the index finger may occasionally be longer than the middle finger. Likewise, the 2nd metatarsal is only rarely affected. There may be other skeletal abnormalities such as short and wide phalanges, bowing, exostoses, and thickening of the calvaria. These patients frequently have calcium deposits and metaplastic bone formation subcutaneously. Moderate degrees of mental retardation, calcification of the basal ganglia, and lenticular cataracts are common in patients who are diagnosed late. serum levels of calcium and phosphorus are normal despite reduced Gsa activity; however, PTH levels may be slightly elevated. 11. Pseudohypoparathyroidismm A. consist raise of PTH level in the presence of hypercalcemia B. is associated with above average intelligence C. is associated with short stature D. has an associated incidence of cataract E..is associated most commonly with shortening of the second metacarpal of the index finger Ans ; CD Affected patients have a genetic defect of the a subunit of the stimulatory guanine nucleotide-binding protein (Gsa ). This coupling factor is required for PTH bound to cell surface receptors to activate cyclic adenosine monophosphate (AMP). The defect is inherited as an autosomal dominant trait, and the paucity of father-to- son transmissions is thought to be due to decreased fertility in males. Affected children have a short, stocky build and a round face. Brachydactyly with dimpling of the dorsum of the hand is usually present. The 2nd metacarpal is involved least often. As a result, the index finger may occasionally be longer than the middle finger. Likewise, the 2nd metatarsal is only rarely affected. There may be other skeletal abnormalities such as short and wide phalanges, bowing, exostoses, and thickening of the calvaria. These patients frequently have calcium deposits and metaplastic bone formation subcutaneously. Moderate degrees of mental retardation, calcification of the basal ganglia, and lenticular cataracts are common in patients who are diagnosed late. Serum levels of calcium are low, and those of phosphorus and alkaline phosphatase are elevated.
  8. 8. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 6 22/12/2017 12. A 12 yr old Hispanic boy with a history of a seizure disorder presents to his pediatrician with complaint of leg cramps. He is of normal stature. His physical examination is unremarkable except for a Chvostek sign. His serum calcium is 6.1 mg/dL with a serum phosphorus level of 9.4 mg/dL. Serum level of intact PTH is 312 pg/mL (normal 10-60 pg/mL). The most likely diagnosis is: A. Primary hyperparathyroidism. B. Pseudohypoparathyroidism type 1B. C. Hypoparathyroidism. D. A calcium-sensing receptor-activating mutation Ans:-B In contrast to the situation in hypoparathyroidism, in pseudohypoparathyroidism (PHP) the parathyroid glands are normal or hyperplastic and they can synthesize and secrete parathyroid hormone (PTH). Serum levels of immunoreactive PTH are elevated even when the patient is hypocalcemic and may be elevated when the patient is normocalcemic. Neither endogenous nor administered PTH raises the serum levels of calcium or lowers the levels of phosphorus. The genetic defects in the hormone receptor adenylate cyclase system are classified into various types depending on the phenotypic and biochemical findings. 13. Which of the following is a feature of pseudohypoparathyroidism? A. Increased urinary phosphate and cAMP with PTH infusion. B. Low serum PTH. C. Low serum calcium and low serum phosphate. D. Low serum calcium and high serum phosphate. E. Shortened 2nd and 3rd metacarpals. Ans:-D Comments: The biochemistry shows a hypocalcaemia with hyperphosphataemia being usual but elevated PTH due to resistance to parathormone (PTH). This is due to mutation of the PTH receptor with abnormality of the Gsalpha subunit with reduced cAMP production following a PTH infusion. There are associated phenotypic signs including short stature, low IQ and shortened 4th and 5th metacarpals. 14. Hypoparathyroidism is associated with: A. increased incidence of Addison's disease. B. chronic mucocutaneous candidiasis. C. basal ganglia calcification, commonly causing Parkinsonism. D. short 4th + 5th metacarpals. E. good response of hypocalcaemia to calcium and vitamin D treatment. Ans:-ABE Comments: Hypoparathyroidism is associated with Addison's disease (autoimmune polyendocrine syndrome type 1 - mucocutaneous candidiasis) as well as other autoimmune conditions - T1DM, hypothyroidism. Short 4th and 5 th metacarpals are associated with pseudohypoparathyroidism. Basal ganglia calcification is common but does not usually cause parkinson's but more likely to cause chorea. The condition is treated with vitamin D. 15. The following are true in parathyroid hormone except ; A. enhance Ca transport from the bone B. inhibite reabsorption of PO4 by renal tubules C. increase transportof Ca by renal tubules
  9. 9. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 7 22/12/2017 D. increase intestinal absorption of Ca Ans ;D When serum levels of calcium fall, the signal is transduced through the calcium-sensing receptor and secretion of PTH ; 1 .increases PTH stimulates activity of 1a-hydroxylase in the kidney, enhancing production of 1,25- dihydroxycholecalciferol (1,25[OH]2 D3 ). The increased level of 1,25[OH]2 D3 induces synthesis of a calcium-binding protein (calbindin-D) in the intestinal mucosa with resultant absorption of calcium. 2. PTH also mobilizes calcium by directly enhancing bone resorption, an effect that requires 1,25[OH]2 D3 . 3. The renal excretion of Ca is inhibited by PTH . The effects of PTH on bone and kidney are mediated through binding to specific receptors on the membranes of target cells and through activation of a transduction pathway involving a G protein coupled to the adenylate cyclase system. Primary roles of vitamin D are facilitation of intestinal absorption of calcium and phosphorus, 16. Feature of Hypoparathyroidism include ; A. Mg toxicity B. metastatic calcification C. Chorieform movement D. constipation E. Brachydactyly Ans ;BC 17. in hypoparathyroidism; A. constipation is characteristic feature B. parathormone is the treatment of choice C. there may be intracranial calcification D. there may be an associated immune deficiency state E, there may be an increased incidence of fungal infections Ans; CDE 18. A 17 year-old female is referred following a visit to the dentist where marked erosion of her teeth was noted. She was entirely asymptomatic and her only medication was the oral contraceptive pill. On examination her blood pressure was 110/70 mmHg and her body mass index was 21.5 kg/m2 (18 - 25). Investigations sodium 135 mmol/l potassium 2.1 mmol/l bicarbonate 42 mmol/l urea 2.6 mmol/L corrected calcium 2.08 mmol/ alkaline phosphatase201 iu/l (50-110) What is the most likely diagnosis? A. Bulimia nervosa. B. Conn's syndrome. C. Laxative abuse. D. Pregnancy. E. Primary hypoparathyroidism. Ans:-E Comments:
  10. 10. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 8 22/12/2017 This patient has tooth erosion associated with hypokalaemic metabolic alkalosis and hypocalcaemia. This suggests a diagnosis of hypoparathyroidism. Conn's is unlikely in this age group, is not associated with tooth erosion and hypertension would be expected. Bulimia like laxative abuse would be associated with hypokalaemia but the hypocalcaemia with raised alkaline phosphatase would not be expected. Early pregnancy would not fit this picture. 19. The following changes occur in ; A. pseudohypoparathyroidism= low Ca , high PO4 , and low PTH B. rickets (Vitamine D deficiency) = high Ca . low PO4 , high alkaline phosphatase , and N/high PTH C. Vitamine D resistant rickets = low PTH , high PO4 D. Hypoparathyroidism = low Ca , low PO4 , and very low PTH E. Vitamine D dependent rickets = low PTH Ans ; all false Serum Ca serum PO4 ALK PTH Hypoparathyroidism low high N low/ zero Pseudohypoparathyroidism low high N/ high high rickets (Vitamine D deficiency) N/low low high high Vitamine D resistant rickets N/low very low high N Vitamine D dependent rickets N/low low high N/high 20. Serum calcium level are ; A. increased by PTH mobilizing Ca from bone B. decreased by vitamin D action on distal renal tubules absorption . C. high in nutritional rickets D. increased by vitamin D mediated absorption from intestinal villi E. low in calcitonin hypersecretion Ans ;AD A 17 year female presents with tingling and muscle cramps. There is no other past medical history of note. Investigations reveal Creatinine 68 micromol/L (50-100) calcium 1.76 mmol/L (2.2-2.6) albumin 38 g/L (37-49) Which one of the following investigations is most likely to confirm the diagnosis? A. Alkaline phosphatase concentration. B. CT brain scanning. C. PTH concentration. D. Urine calcium concentration. E. Vitamin D concentration. Ans:-C Comments: This patient has low calcium which could be due to either Vitamin D deficiency orhypoparathyroidism. The most likely cause in a young patient who has otherwise been quite well with normal renal function would therefore be hypoparathyroidism. Urine calcium concentrations are useful in familial hypercalciuric hypercalcaemia.
  11. 11. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 9 22/12/2017 21. A 15-year-old boy has been immobilized in a double hip spica cast for 6 weeks after having fractured his femur in a skiing accident. He has become depressed and listless during the past few days and has complained of nausea and constipation. He is found to have microscopic hematuria and a blood pressure of 150/100 mm Hg. Which of the following is the most appropriate course of action? A. Request a psychiatric evaluation. B. Check blood pressure every 2 hours for 2 days. C. Collect urine for measurement of the calcium to creatinine ratio. D. Order a renal sonogram and intravenous pyelogram (IVP). E. Measure 24-hour urinary protein Ans:-C Hypercalcemia can develop in children who are immobilized following the fracture of a weight-bearing bone. Serious complications of immobilization hypercalcemia, and the hypercalciuria that occurs as a result, include nephropathy, nephrocalcinosis, hypertensive encephalopathy, and convulsions. The early symptoms of hypercalcemia namely, constipation, anorexia, occasional vomiting, polyuria, and lethargy are nonspecific and may be ascribed to the effects of the injury and hospitalization. Therefore, careful monitoring of these patients with serial measurements of the serum ionized calcium and the urinary calcium to creatinine ratio is critical during their immobilization. A ratio of greater than 0.2 establishes a diagnosis of hypercalciuria. Although complete mobilization is curative, additional measures, such as vigorous intravenous hydration with a balanced salt solution, dietary restrictions of dairy products, and administration of diuretics, can be instituted. For patients who are at risk for symptomatic hypercalcemia, short-term therapy with calcitonin is highly effective in reducing the concentration of serum calcium by inhibiting bone resorption. 22. Which of the following are recognised complications of dietary calcium deficiency? A. Rickets B. Neonatal seizures C. Failure of nail growth D. Cataracts E. Neonatal tetany Ans:-ABE Nutritional calcium deficiency in childhood rarely occurs in isolation, so that there is limited information covering its consequences. It has been suggested that deficient intake results in growth retardation. Juvenile osteoporosis has been reported in pre-pubertal children but does not seem to have a nutritional basis. The most frequently reported disturbance is neonatal hypocalcemia and this may be associated with seizures. The disturbances of calcium metabolism associated with rickets and steatorrhea are usually related to vitamin D deficiency, although hypocalcaemia due to dietary calcium deficiencies has been described. 23. All of the following are feature of hypocalcemic tetany except; A. laryngospasm B. apnea C. tachycardia D. prolonged QT interval E. muscular twitching Ans ; C 24. A 12 year old child presents with pelvic pain and bowing of the tibia. A diagnosis of osteomalacia is suspected. Which one of the following statements is true regarding osteomalacia?
  12. 12. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 10 22/12/2017 A. Bone biopsy would show an increase in mineralised osteoid. B. Is due to vitamin A deficiency. C. May present with pseudo-fractures. D. Serum calcium is increased. E. Typically causes a distal myopathy. Ans:-C Comments: Osteomalacia is due to vitamin D deficiency. It can result from malabsorption, renal disease (familial hypophos-phataemic rickets), chronic renal failure and anticonvulsant therapy. It often presents with bone pain and a proximal myopathy. The psuedo-fractures in the hip are termed Looser’s zones. Serum calcium is low. A bone biopsy would show an decrease in the amount of mineralised osteoid. 25. Rickets may be due to ; A. lack of sunshine B. celiac disease C. excessive urinary phosphate excretion D. chronic renal failure E. lack of vitamine A Ans ; ABCD excessive urinary phosphate excretion is secondary to increased PTH activity → low serum Po4 level 26. The following are characteristic features of rickets; A. decreased bone density on X ray B. N/↓ alkaline phosphatase C. widening and fraying of epiphyses on X-ray D. raised serum phosphate E. subperiosteal new bone formation Ans ; AC 27. Children particularly at risk for rickets include:- A. Those born small for gestational age. B. Asian infants living in Britain fed formula milk. C. Those with Hirschsprung’s disease. D. Mentally handicapped children with epilepsy taking long-term anticonvulsants. E. Those with severe renal insufficiency Ans:-DE Comments: Small for gestational age infants are not at increased risk, of vitamin D deficiency, which is usually, the combined result of deficient sun exposure and decreased dietary intake. Breast fed Asian infants are at increased risk. Hirschprungs disease affects the large bowel and not small. Anti convulsants can cause osteomalacia by reducing 25 hydroxylation of vitamin D in the liver. 28. The following statements have been made about early nutritional rickets: A. It can be prevented by a daily intake of 400 iu vitamin D. B. Serum calcium is reduced. C. Serum alkaline phosphatase is elevated. D. Bowing of legs is pathognomonic. E. Hypotonia is a clinical feature.
  13. 13. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 11 22/12/2017 Ans:- ACE Comments: 400 iu Vitamin D is more than adequate to prevent rickets in children, Serum calcium is either normal or may be at the lower end of normal. Serum alkaline phosphatase is elevated because of increased osteoblastic activity. Bowing of the legs may be familial and is not necessarily always caused by rickets. Hypotonia can occur due to alterations in muscle phosphorus ratios. 29. 1, 25, dihydroxycholecalciferol: A. Causes suppression of parathyroid hormone (PTH) by direct action on the parathyroid gland. B. Causes suppression of parathyroid hormone indirectly by increasing serum calcium. C. Acts on cell surface receptors. D. Is biologically more active than 25, dihydroxycholecalciferol. E. Leads to increased osteoblast activity. Ans:-BCD Comments: 7, dihydrocholesterol is converted by sunlight into cholecalciferol (Vitamin D3). In the liver this is 25, hydroxylated, and in the kidney this is 1, 25 hydroxylated. Vitamin D is not abundant in natural foods except for fish liver oils, fatty fish and egg yolk. Ergocalciferol (Vitamin D2) is used to fortify margarine. 1, 25 dihydroxycholecalciferol is the most active form of the vitamin. It is produced following parathormone secretion in response to a low plasma calcium. The effect of 1, 25 (OH2D3) is to induce synthesis of a calcium binding protein (calbindin-D) in the intestinal mucosa with the resultant absorption of calcium. It also promotes bone dissolution and mineralisation. Thyroid hormones also mobilises calcium by directly enhancing bone resorption, an effect that requires 1, 25 dihydroxy Vitamin D. The effects of PTH on bone and kidney are mediated through binding to specific receptors on the membranes of target cells and through activation of the transduction pathway involving a G protein coupled with an adenelatecyclase system. Steroid hormones also work through binding to specific receptors on the cell surface and then influencing DNA transcription and translation in the cell nucleus. 30. A 17 year old female who is 16 weeks pregnant reports that her elder brother has vitamin D reisistant rickets. What is the most likely mode of inheritance of this condition? A. Autosomal dominant. B. Autosomal dominant with incomplete penetrance. C. Autosomal recessive. D. X-linked dominant. E. X-linked recessive. Ans:-D Vitamin D resistant rickets is inherited in an X-linked dominant manner. Therefore an affected female will transmit the disease to 50% of her sons and 50% of her daughters. An affected male will transmit the condition to all of his daughters but none of his sons. In this case as the mother is unaffected, therefore there is no risk of the condition being passed to her unborn child. 31. Which of the following are recognised complications of dietary calcium deficiency? A. Rickets. B. Neonatal seizures. C. Failure of nail growth.
  14. 14. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 12 22/12/2017 D. Cataracts. E. Neonatal tetany. Ans:-ABE Nutritional calcium deficiency in childhood rarely occurs in isolation, so that there is limited information covering its consequences. It has been suggested that deficient intake results in growth retardation. Juvenile osteoporosis has been reported in pre-pubertal children but does not seem to have a nutritional basis. The most frequently reported disturbance is neonatal hypocalcemia and this may be associated with seizures. The disturbances of calcium metabolism associated with rickets and steatorrhea are usually related to vitamin D deficiency, although hypocalcaemia due to dietary calcium deficiencies has been described. 32. An 8-month-old infant presents with the primary complaint of irritability. He has been exclusively breastfed since birth. His mother was not interested in providing any supplemental foods because her milk supply has been adequate. Physical examination reveals a fussy infant who has frontal bossing and whose weight and height are both at the 25th percentile. The infant becomes irritable with movement of the left arm. Arm radiography reveals a humeral fracture and bowing of both radii. Chest radiography demonstrates enlargement of the costochondral junctions. Of the following, the MOST likely diagnosis is A. congenital syphilis B. osteogenesis imperfecta C. vitamin D-deficient rickets D. vitamin D-resistant rickets E. vitamin E deficiency Ans:-C Older infants eating a restricted diet or receiving a single nutritional source may be at risk for micro- nutrient deficiencies. For example, children raised on vegan diets are at risk for vitamin B12 defici- ency, and children fed with goat’s milk are at risk for folate deficiency. The clinical presentation and radiographic findings (Item C2A) described for the exclusively breastfed infant in the vignette suggest vitamin D-deficient rickets. Congenital syphilis (Item C2B), vitamin D-resistant rickets, and osteo- genesis imperfecta (Item C2C) all can present with skeletal abnormalities, but these conditions are less common than vitamin D-deficient rickets and typically have additional clinical findings. Vitamin E deficiency presents with neuropathy and hemolysis rather than skeletal abnormalities. There are two primary forms of vitamin D: vitamin D2 is added to milk and multivitamin preparations, and vitamin D3 is synthesized endogenously in humans from 7-dehydrocholesterol via a photochemical reaction that requires exposure to the ultraviolet B radiation found in sunlight. Humans living at high latitudes produce very little vitamin D3 from November to March. Vitamin D is hydroxylated to 25- hydroxyvitamin D in the liver and converted to 1,25-dihydroxyvitamin D in the renal tubular epithelium. Vitamin D status usually is assessed by measurement of the 25-hydroxyvitamin D form; a concentration of less than 20 ng/mL (50 nmol/L) is considered vitamin D insufficiency, and less than 15 ng/mL (37 nmol/L) is considered deficiency. Biochemical complications of vitamin D deficiency include reduced calcium and phosphorus absorption, increased para-thyroid hormone secretion, and phosphaturia. Initially, infants who have vitamin D-deficient rickets have normal serum calcium, low phosphorus, elevated alkaline phosphatase, and low 25-hydroxyvitamin D values. Presenting clinical features of vitamin D-deficient rickets in infancy include fractures, irritability, and rarely, seizures from hypocalcemia. There is little vitamin D in human milk, and if an infant does not receive either vitamin D supplementation or adequate sun exposure, rickets may occur. African- American infants and children from higher latitudes are at increased risk for this condition. Therefore,
  15. 15. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 13 22/12/2017 the American Academy of Pediatrics Committee on Nutrition recommends the administration of 200 IU/d of supplementary vitamin D to infants older than 2 months of age until they are weaned to at least 500 mL/d of formula. 33. Low serum magnesium can occur in the following: A. Spironolactone treatment. B. Alcoholism. C. Hypocalcaemia. D. Diabetic ketoacidosis. E. Polyuric acute tubular necrosis Ans:-BCDE Hypomagnesaemia is a feature of malabsorption syndromes, hypoparathyroidism, hypercalcaemia, hypocalcaemia, renal tubular acidosis, primary hyperaldosteronism, and alcoholism. It can occur because of prolonged diuretic therapy, through use of nephrotoxic agents, and because of prolonged intravenous therapy, particularly in infants, using non-magnesium containing fluids. It is often associated with tetany. The symptoms are predominantly of neuromuscular irritability, with tetany, fits and cardiac rhythm disturbances. Neonatal tetany may not resolve until hypomagneseamia has been treated. 34. Hypomagnesaemia can be caused by: A. Loop diuritics. B. Amphotericin B C. Co- amoxiclav D. Alcohol. E. Cyclosporin. Ans:-ABDE Approximately 60%of total body magnesium resides in bone, 20% in muscle, and the remainder in soft tissues including the liver. 99% of magnesium is intracellular. Decreased magnesium can be due to decreased intake, decreased absorption, and gastrointestinal or renal losses. Chronic small intestinal malabsorption due to enteritis. Diarrhea, small bowel bypass surgery or chronic pancreatitis is a cause of hypomagnesaemia. Renal losses are often associated with the administration of loop diuretics which inhibit magnesium reabsorption in the thick ascending limb of the loop of henle. Amphotericin B and cyclosporin also impair reabsorption of magnesium in the loop of henle and distal tubule. In addition, these drugs are nephrotoxic- further disrupting renal magnesium homeostasis. Alcohol abuse is associated with hypomagnesaemia. In alcohol abuse: *Poor diet is associated with decreased magnesium intake. *?Intestinal absorption is decreased by lipid malabsorption which accompanies chronic pancreatitis and cirrhosid. 35. Raised serum inorganic phosphorous is found in:- A. Acromegaly. B. renal tubular acidosis. C. dietary rickets. D. pseudo-hypoparathyroidism. E. chronic obstructive jaundice.
  16. 16. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 14 22/12/2017 Ans:_AD Hyperphosphataemia is associated with Acromegaly as GH causes phosphate reabsorption. Pseudo- hypoPTH is also associated with hyperphosphataemia. b+c Phosphate is low. 36. Hypophosphataemia is associated with:- A. Vitamin D therapy. B. Diabetic ketoacidosis. C. Metabolic alkalosis. D. Minimal change glomerulonephritis. E. Sucrose-isomaltase deficiency. Ans:-BC Comments: Hypophosphataemia is associated with: • Decreased intake: premature neonate, starvation or protein energy malnutrition, malabsorption. • Fluid or electrolyte shifts: respiratory/metabolic alkalosis, diabetic ketoacidosis, steroid therapy. • Increased losses: primary and tertiary hyperparathyroidism, renal tubular defects, diuretic therapy, post intravenous fluids. • Combination: Vitamin D deficiency, Vitamin D resistant rickets. ………………………………………………………………………………………………………… 37. The thyroid hormone receptor is: A. A gated ion channel. B. A cell surface receptor. C. A cytoplasmic protein. D. A G-protein coupled receptor. E. A nuclear receptor Ans:-E Comments: The thyroid hormone receptor is a nuclear receptor. When it binds T3 it is able to bind to the thyroid hormone response element (TRE) in the promoter region of thyroid hormone responsive genes and initiates transcription. 38. features of Childhood hypothyroidism (CRETINISM) A. wide fontanelles. B. periosteal reaction. C. anterior tibial bowing. D. Bone marrow edema. E. delayed pneumatization of sinuses. Ans:-AE 39. Congenital hypothyroidism, the most common cause:- A. Agenesis of the thyroid gland. B. Dysgenesis of the thyroid gland. C. Maternal iodine deficiency. D. Defect of thyroxine synthesis. Ans:-B 40. The following statements are true: A. Dyshormonogenesis is the commonest cause of congenital hypothyroidism.
  17. 17. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 15 22/12/2017 B. In patients with short stature (height below the 3rd centile) one should always screen for growth hormone efficiency. C. Congenital adrenal hyperplasia is a cause of ambiguous genitalia in the newborn. D. Children with diabetes mellitus always require treatment with insulin. E. Onset of puberty is usually earlier in boys than in girls. Ans:-C Comments: The commonest causes of congenital hypothyroidism are thyroid aplasia/hypoplasia or ectopic thyroid gland. Short stature may be the consequence of multiple factors and Growth hormone deficiency is identified in a minority of patients. Growth velocity, parental height, intercurrent illnesses and use of drugs such as steroids may be more relevant. In females with congenital adrenal hyperplasia, excessive adrenal androgens result in virilisation and ambiguous genitalia. The incidence of type 2 diabetes in children is rising, and children may be treated with weight loss/diet and or metformin. Also in the condition known as MODY (maturity onset diabetes of the young, autosomal dominant, defective insulin secretion) oral hypoglycaemics are used initially. The onset of puberty is delayed by approximately 2 years in males, when compared to females. 41. Which one of the following statements is true concerning congenital hypothyroidism: A. Bone age is usually normal. B. Has an incidence of 1 in 15,000. C. Is a cause of bilateral inguinal hernia. D. Requires children to be placed in special schooling. E. Is best monitored by regular assessment of height velocity. Ans:-E Comments: Congenital hypothyroidism is associated with delayed bone age. The incidence is one in 4000. The condition is associated with umbilical herniae and not inguinal herniae. Intellectual function and cognitive development may be impaired if the condition remains untreated or in cases of severe cretinism, which is rare. The rate of linear growth is retarded in this condition and is always less than weight gain. 42. Which of the following is commonly associated with congenital hypothyroidism in the neonatal period: A.Hypothermia. B.Diarrhoea. C.Prolonged conjugated hyperbilirubinaemia. D.A small anterior fontanelle. E.Inguinal hernia. Ans:-A Comments: Hypothermia results from reduced metabolic rate. Constipation rather than diarrhoea is a common clinical feature. Prolonged conjugated hyperbilirubinaemia is a relatively uncommon sequelae. The anterior fontanelle would be tense. Umbilical rather than inguinal herniae are associated. 43. Most common cause of congenital hypothyroidism is:- A. Dysgenesis of the thyroid gland. B. Maternal iodine deficiency. C. Maternal iodine ingestion.
  18. 18. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 16 22/12/2017 D. Defect in thyroxine synthesis E. Hashimoto thyroiditis. Ans:-A 44. Three years old boy presented with goiter, short stature, deafness and symptoms suggestive of mild hypothyroidism. On examination, was having normal mentality, diffuse goiter, deaf and mute with normal CNS examination apart from sluggish reflexes. His bone age was retarded and has raised level of circulating TSH, fT4 and fT3. Among which of the following is most likely diagnosis? A. Generalized resistance to thyroid hormone (GRTH) B. Pituitary resistance to thyroid hormone (PRTH) C. Pendred's syndrome D. TSH secreting Adenoma E. Congenital thyroid hypoplasia Ans: C 45. The state laboratory calls your office telling you that a newborn infant, now 8 days old, has an elevated thyroid stimulating hormone (TSH) and low thyroxin (T4) on his newborn screen. If this condition is left untreated, the infant is likely to demonstrate which of the following in the first few months of life? A. Hyperreflexia. B. Hyperirritability. C. Diarrhea. D. Prolonged jaundice. E. Hyperphagia Ans:-D Signs of congenital hypothyroidism include constipation, prolonged jaundice, sluggishness, poor feeding, apnea, choking, macroglossia, and excessive sleepiness. The physical examination is usually normal early on except for mild jaundice and a distended abdomen in a sleepy infant. The most appropriate step to manage this condition is to avoid delays and to initiate oral sodium- L -thyroxine, 10 - 15 μg/kg/day. Thyroid dysgenesis is found in 90% of the cases. Neonatal screening for hypothyroidism has allowed for the much earlier diagnosis of hypothyroidism, resulting in an improved prognosis, so that frank cretinism is now quite rare. Most industryalized countries test for phenylketonuria and hypothyroidism; there is variability in testing for other metabolic and genetic diseases. 46. A goitre in a neonate could be caused by the following conditions: A. Fetal alcohol syndrome. B. Maternal thyrotoxicosis. C. Maternal antithyroid medication. D. Maternal lithium treatment. E. Maternal thyroxine ingestion. Ans:- BCD Comments: Defective synthesis of T4 or defects of iodide uptake. Maternal iodides, antithyroid drugs, lithium, amiodarone Maternal iodine deficiency (endemic goitre) Maternal Graves disease (congenital hyperthyroidism) Thyroid teratoma Congenital goitre is usually sporadic and may result from the administration of antithyroid drugs or iodides during pregnancy for the treatment of thyrotoxicosis. Goitrogenic drugs and iodides cross the placenta and at high doses may interfere with synthesis of
  19. 19. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 17 22/12/2017 thyroid hormone, resulting in goitre and hypothyroidism in the fetus. The concomitant administration of thyroid hormone with the goitrogen does not prevent this effect, because insufficient amounts of thyroxine (T4) cross the placenta. Iodides are included in many proprietary preparations used to treat asthma; these preparations must be avoided during pregnancy, because they have often been a cause of unexpected congenital goitre. Amiodarone, an antiarrhythmic drug with a 37% iodine content, has also caused congenital goitre with hypothyroidism. Lithium carbonate also causes goitres; it is currently widely used as a psychotropic drug. Lithium competes with iodide; the mechanism producing the goitre or hypothyroidism is similar to that described earlier for iodide goitre. Lithium and iodide also act synergistically to produce goitre; their combined use should be avoided. Amiodarone, a drug used to treat cardiac arrhythmias, can cause thyroid dysfunction with goitre because it is rich in iodine. It is also a potent inhibitor of 5´- deiodinase, preventing conversion of T4 to T3. It can cause hypothyroidism, particularly in patients with underlying autoimmune disease; in other patients, it may cause hyperthyroidism. 47. The presence of goiter at birth is usually the result of ; A. ingestion of goiterogenics substance by the mother B. congenital hypothyroidism C. sever peroxidase deficiency D. thyroglossal duct abnormality E. thyroiditis congenita Ans ; AC A goiter is an enlargement of the thyroid gland, Congenital goiter is usually sporadic and may result from a fetal thyroxin (T4 ) synthetic defect or the administration of antithyroid drugs or iodides during pregnancy for the treatment of thyrotoxicosis. Goitrogenic drugs and iodides cross the placenta and at high doses may interfere with synthesis of thyroid hormone, resulting in goiter and hypothyroidism in the fetus. Iodides are included in many proprietary preparations used to treat asthma; these preparations must be avoided during pregnancy because they have often been a cause of unexpected congenital goiter. Amiodarone, an antiarrhythmic drug with a 37% iodine content, has also caused congenital goiter with hypothyroidism. Even when the infant is clinically euthyroid, there may be retardation of osseous maturation, low levels of T4 , and elevated levels of thyroid-stimulating hormone (TSH) . other goitrogens include thiouracil , sulfonamide , and hematinic medication containing cobalt . 48. Neonatal goitre may be caused by:- A. antithyroid drugs given to the mother. B. prolonged use of iodide-containing medicines by the mother. C. maternal smoking. D. an inborn error of metabolism. E. thyroxine given to the mother. Ans:-ABD Comments: Neonatal goitre may be caused by the following: Maternal drugs such as carbimazole, iodine containing compounds Certain inborn errors of thyroid metabolism (such as Pendred's syndrome). Maternal Graves disease due to the passage of TSH receptor antibodies across the placenta which will cause thyroid enlargement. Giving thyroxine to the mother would not be expected to cause a goitre nor is maternal smoking associated with goitre.
  20. 20. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 18 22/12/2017 49. The causes of goitrus hypothyroidism:- A. Hashimoto thyroiditis. B. Dyshormonogenesis. C. Drug induced. D. Iodine deficiency. E. Pendred syndrome. Ans:-ABCDE 50. The following may result in goiter formation:- A. Repeated metaiodobenzylguanidine scan (MIBG) for neuroblastoma. B. Pendred’s syndrome. C. Maternal goitrogen. D. Ectopic positioning of the gland. E. Diffuse thyroid carcinoma. Ans:-BCE 51. With regard to hypothyroidism:- A. Dyshormonogenesis is the most common cause of congenital hypothyroidism. B. Dyshormonogenesis may involve problem of failure to incorporate iodine in order to produce thyroxine. C. Screening for congenital hypothyroidism is performed on children from high risk families. D. Screening involves the estimation of TSH. E. Screening operates as negative reporting system in the UK. Ans:-B 52. Clinical sign of hypothyroidism include:- A. Sever constipation. B. Tachycardia secondary to heart failure. C. Reduced IQ. D. Angular cheilitis. E. Dry skin Ans:-ACE 53. all of the following are characteristic of congenital hypothyroidism except ; A. Infant are born with little or no evidence of thyroid hormone deficiency B. classic facies is result of accumulation of myxedema in subcutaneous tissues and tongue C. prolonged hypothyroidism result in muscular hypotonia and mental defect D. T4 value are low and TSH conc. are high in newborn E. The best guide to measure effectiveness of therapy is to observe physical changes Ans ;E Most infants with congenital hypothyroidism are asymptomatic at birth, even if there is complete agenesis of the thyroid gland. This situation is attributed to the transplacental passage of moderate amounts of maternal T4 , which provides fetal levels that are 33% of normal at birth. These low serum levels of T4 and concomitantly elevated levels of TSH make it possible to screen and detect most hypothyroid neonates, Before neonatal screening programs, congenital hypothyroidism was rarely recognized in the newborn because the signs and symptoms are usually not sufficiently developed . Levels of T4 and TSH should be monitored at recommended intervals and maintained in the normal range for age , Later, confirmation of the diagnosis may be necessary for some infants to rule out the possibility of transient hypothyroidism. This is unnecessary in infants with proven thyroid ectopia or in those who manifest elevated levels of TSH after 6–12 mo of therapy because of poor compliance or an inadequate dose of T4 .
  21. 21. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 19 22/12/2017 Discontinuation of therapy at about 3 yr of age for 3–4 wk results in a marked increase in TSH levels in children with permanent hypothyroidism. 54. Congenital hypothyroidism: A. Cannot be diagnosed clinically before 3 months of age. B. May be associated with an ectopic thyroid gland. C. Needs life-long Thyroxine replacement. D. Can present in the newborn period with haemolytic jaundice. E. If undiagnosed causes short stature but with a normal bone age. Ans:-BC Comments: Patients with congenital hypothyroidism may exhibit non specific clinical features e.g. jaundice and poor feeding however macroglossia is a fairly specific clinical finding aiding diagnosis. The commonest causes of congenital hypothyroidism are an absent or ectopic gland. The need for thyroxine is life long. The hyperbiliru-binaemia is conjugated and ‘haemolytic jaundice’ would not occur. Short stature and delayed bone age occur. 55. Congenital hypothyroidism A. is usually the result of autosomal recessive inheritance B. is amenable to detection by specific & sensitive screening program C. is usually associated with goiter D. is caused by maternal iodine deficiency E. is associated with prolonged gestation Ans; BDE Some form of thyroid dysgenesis (aplasia, hypoplasia, or an entopic gland) is the most common cause of congenital hypothyroidism, accounting for 85% of cases; 10% are caused by an inborn error of thyroxine synthesis, and 5% are the result of transplacental maternal thyrotropin-receptor blocking antibody Thyroid dysgenesis occurs sporadically, but familial cases have occasionally been reported. In neonates with congenital hypothyroidism due to thyroid dysgenesis, 2% of cases are familial; thus, 98% are sporadic A variety of defects in the biosynthesis of thyroid hormone may result in congenital hypothyroidism; when the defect is incomplete, compensation occurs, and onset of hypothyroidism may be delayed for years. A goiter is almost always present, and the defect is detected in 1/30,000–50,000 live births in neonatal screening programs. These defects are transmitted in an autosomal recessive manner. iodine deficiency or endemic goiter is the most common cause of congenital hypothyroidism worldwide. it arises as sporadic disorder. Most infants with congenital hypothyroidism are asymptomatic at birth, even if there is complete agenesis of the thyroid gland , The clinician is dependent on neonatal screening tests for diagnosis of congenital hypothyroidism Prolonged gestation is common in congenital hypothyroidism . 56. Which of the following statements applies to congenital hypothyroidism. A. Cannot be diagnosed clinically before 3 months of age. B. May be associated with an ectopic thyroid gland. C. Thyroxine may be discontinued after a period of treatment. D. Can present in the newborn period with haemolytic jaundice. E. If undiagnosed causes short stature but with a normal bone age.
  22. 22. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 20 22/12/2017 Ans:-B Comments: Patients with congenital hypothyroidism may exhibit non-specific clinical features e.g. jaundice and poor feeding however macroglossia is a fairly specific clinical finding aiding diagnosis. The commonest causes of congenital hypothyroidism are an absent or ectopic gland. The need for thyroxine is life long. The hyperbiliru-binaemia is conjugated and ‘haemolytic jaundice’ would not occur. Short stature and delayed bone age occur. 57. Congenital hypothyroidism ; A. is usually due to dyshormonogenesis B. is usually symptomatic in the neonatal period C. incidence is 1 in 4000 D. high TSH , normal T4 on treatment suggest poor compliance E. screening is at the 6 week check Ans ; CD Neonatal screening is with the Guthrie card test for phenylketonuria at 7- 10 days . in most areas both T4 and TSH are assayed , usually T4 will be low & TSH raised although in 10% the T4 will be normal . Neonatal screening will not usually detect hypothyroidism due to TSH deficiency. Because 80% of circulating T3 is formed by monodeiodination of T4 , serum levels of T4 and T3 in treated infants return to normal. This is also true in the brain, where 80% of required T3 is produced locally from T4 , Levels of T4 and TSH should be monitored at recommended intervals and maintained in the normal range for age , normal T4 should be aimed for , but the TSH doesn't necessary have to be normal . High TSH and normal T4 suggest poor compliance , Serum T4 or FT4 concentrations should be used to monitor the adequacy of therapy initially, because the elevated TSH may not fall into the normal range for several days to weeks. Subsequently, T4 and TSH are used in combination, as elevations of serum TSH are sensitive early indicators of the need for increased medication (or increased compliance). Later, confirmation of the diagnosis may be necessary for some infants to rule out the possibility of transient hypothyroidism. This is unnecessary in infants with proven thyroid ectopia or in those who manifest elevated levels of TSH after 6– 12 mo of therapy because of poor compliance or an inadequate dose of T4 The only untoward effects of sodium-l-thyroxin are related to its dose. Over treatment may risk craniosynos- tosis and temperament problems. An occasional older child (8–13 yr) with acquired hypothyroidism may experience pseudotumor cerebri within the first 4 mo of treatment. In older children, after catch-up growth is complete, the growth rate provides an excellent index of the adequacy of therapy. Parents should be forewarned about changes in behavior and activity expected with therapy, and special attention must be given to any developmental or neurologic deficits. 58. An 18 month old boy investigated for failure to thrive and delayed development is found to have primary hypothyroidism. Which of the following statements applies to his condition. A. He is unlikely to achieve normal intelligence despite immediate commencement of appropriate treatment. B. If his bone age was 3 months the onset of his hypothyroid state is most likely to have occurred at 3 months of age. C. Growth hormone deficiency is likely also to be associated. D. Hashimoto’s disease is the most likely cause. E. He is more prone to develop parathyroid insufficiency. Ans:-A Comments:
  23. 23. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 21 22/12/2017 The diagnosis of congenital hypothyroid ism has been delayed and hence thyroxine therapy will not restore mental function fully. The hypothyroidism is likely to have been present at birth. Growth hormone deficiency may be seen in association with secondary hypothyroidism if pituitary insufficiency exists, but not in primary hypothyroidism. The most likely aetiology is absent or ectopic thyroid. Hypoparathyroidism is unrelated. 59. Congenital hypothyroidism; A. occur in 1 in 10 000 birth B. has an increased incidence in infant with Down syndrome C. is most commonly caused by inborn error of thyroid hormone biosynthesis D. is always detectable by screening at day 5-7 on dried blood spot E. is not associated with developmental delay if treatment is initiated within the first 12 week of life . Ans; B Screening with Guthrie card at 5-7 days , All cases are not detected because 1 in 100 cases will be due to hypothalamic – pituitary problem and therefore TSH will not be elevated, the screen relies on an elevated TSH . Early diagnosis and adequate treatment from the first weeks of life result in normal linear growth and intelligence comparable with that of unaffected siblings. Without treatment, affected infants become profoundly mentally deficient dwarfs. Thyroid hormone is critical for normal cerebral development in the early postnatal months; biochemical diagnosis must be made soon after birth, and effective treatment must be initiated promptly to prevent irreversible brain damage. Delay in diagnosis, failure to correct initial hypothyroxinemia rapidly, inadequate treatment, and poor compliance in the first 2–3 yr of life result in variable degrees of brain damage When onset of hypothyroidism occurs after 2 yr of age, the outlook for normal development is much better even if diagnosis and treatment have been delayed, indicating how much more important thyroid hormone is to the rapidly growing brain of the infant 60. In congenital hypothyroidism:- A. Mostly due to developmental defect in the thyroid gland (dysgenesis) B. Girls are commonly affected C. Is reliably detected by biochemical investigations in the first week of life. D. Is reliably detected by clinical examination in the first week of life. E. Can cause delay in bone maturation Ans:-ABCE 61. The following clinical features are commonly associated with congenital hypothyroidism in the neonatal period: A. Hypothermia. B. Diarrhoea. C. Prolonged conjugated hyperbilirubinaemia. D. A small anterior fontanelle. E. Inguinal hernia. Ans:-A Comments: Hypothermia results from reduced metabolic rate. Constipation rather than diarrhoea is a common clinical feature. Prolonged conjugated hyperbilirubinaemia is a relatively uncommon sequelae. The anterior fontanelle would be tense. Umbilical rather than inguinal herniae are associated.
  24. 24. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 22 22/12/2017 62. A 2 week old baby is thought to have hypothyroidism because of the following clinical feature A. microglossia B. prolonged jaundice C. diarrhea D. maternal Graves disease E. wide posterior fontanelle Ans; BE 63. Clinical feature of congenital hypothyroidism diagnosed in newborn period include; A. large tongue B. presence of third fontanelle C. umbilical hernia D. loose stool E. high incidence of mental retardation Ans ; AC 64. The following features suggest congenital hypothyroidism: A. poor sleep pattern. B. irritable child. C. neonatal seizures. D. a hoarse cry. E. an exaggerated Moro reflex. Ans:-D 65. Which of the following are characteristic feature of congenital hypothyroidism ; A. low birth weight B. exomphalos C. prolonged neonatal unconjugated hyperbilirubinemia D. normal appearance E. goiter Ans ; CD Only 5% of infected infant exhibit clinical signs within the first week of life hence the need for screening. Even with congenital absence of the thyroid gland, most newborns appear normal at birth and gain weight normally for the first 3–4 months of life, even without treatment. As congenital hypothyroidism must be treated as early as possible to prevent intellectual impairment, the diagnosis should be based on the newborn screening test and not on abnormal physical findings. 66. The following symptoms in an infant in the first month of life should alert one to the possibility of hypothyroidism ; A. prolonged jaundice B. vomiting C. diarrhea D. hoarse cry E. voracious appetite Ans ;AD 67. A newborn infant is found to be hypothyroid on a new born screening test. Which one of the following is the most likely cause? A. Defective thyroglobukin iodination B. Deficiency of thyroid stimulating hormone. C. Impaired foetal iodine transport. D. Maternal autoantibodies.
  25. 25. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 23 22/12/2017 E. Thyroid dysgenesis. Ans:-E Thyroid developmental defects (thyroid dysgenesis) are the commonest causes of congenital hypothyroidism accounting for 80-85 % of cases. Enzyme defects or dyshormonogenesis are next 15 %. Incidence of congenital hypothyroidism is between 1 in 3,500 -4,500. 68. Regarding congenital hypothyroidism:- A. It is much less common than phenylketonuria. B. It is due to dyshormogenesis in about 10% of cases. C. Hypothyroidism due to TSH deficiency is very rare. D. Despite early treatment, a few patients have severe learning difficulties. E. Neonatal screening detects about 95% of cases. Ans:-BC Comments: The neonatal screening programme for congenital hypothyroidism is a major recent triumph for Paediatrics. It is one of the most common of the metabolic defects, detection is virtually complete, and the long term outcome should be an IQ within the normal range. Causes of congenital hypothyroidism include: • Athyrosis. • Maldescent. • Dyshormonogensis (10%). • Iodine deficiency (commonest worldwide, but rare in the UK because of iodination of salt). • TSH deficiency (usually associated with panhypopituitarism, very rare). 69. Neonatal symptoms / signs which should raise suspicion of hypothyroidism : A. Lack of attention B. Coarse features, C. Hoarse cry. D. Absent epiphyseal ossification at knee joint E. Unresolved physiological jaundice. Ans:- ABCDE 70. An 18 month old boy investigated for failure to thrive and delayed development is found to have primary hypothyroidism: A. He is unlikely to achieve normal intelligence despite immediate commencement of appropriate treatment. B. If his bone age was 3 months the onset of his hypothyroid state is most likely to have occurred at 3 months of age. C. Growth hormone deficiency is likely also to be associated. D. If untreated, he has a higher chance of developing atherosclerot ic heart disease. E. He is more prone to develop parathyroid insufficiency. Ans:-AD Comments: The diagnosis of congenital hypothyroidism has been delayed and hence thyroxine therapy will not restore mental function fully. The hypothyroidism is likely to have been present at birth. Growth hormone deficiency may be seen in association with secondary hypothyroidism if pituitary
  26. 26. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 24 22/12/2017 insufficiency exists, but not in primary hypothyroidism. Untreated hypothyroidism is associated with dyslipidaemia and cardiovascular disease. Hypoparathyroidism is unrelated. 71. Congenital hypothyroidisrn is associated with: A. Prolonged neonatal jaundice B. Constipation. C. Mental retardation. D. Underweight E. Anemia Ans:-ABCE 72. Regarding congenital hypothyroidism: A. Epiphyseal dysgenesis is an association B. Prolonged neonatal jaundice is a recognized manifestation. C. Diarrhea is a recognized feature. D. Delayed treatment causes mental retardation. E. Many causes is usually present Ans:-ABD 73. Congenital hypothyroidism A. cannot confidently be diagnosed before the age of three months. B. is in some cases associated with a goiter. C. affects approximately 1 in 10,000 infants. D. may present with jaundice. E. requires thyroxine treatment throughout life. Ans:-BDE 74. Cretinism is characterised by A. premature fusion of epiphyses. B. persistance of jaundice in neonate. C. delayed dentition. D. paralytic ileus. E. incidence about 1:200. Ans:-BCD Comments: a-retarded bone age, e-1:5000. Also short stature, protruding tongue, broad flat nose, widely set eyes, sparse hair, dry skin, protruberant abdomen, umbilical hernia. 75. Congenital hypothyroidism: A. Is normally treated using the L-isomer of Thyroxine B. Has an incidence of 1 in 15,000 C. Is a cause of bilateral inguinal herniae D. Requires children to be placed in special schooling E. Is best monitored by regular assessment of height velocity Ans:-AE Comments: Congenital hypothyroidism is treated using L thyroxine. The incidence is one in 4000. The condition is associated with umbilical herniae and not inguinal herniae. Intellectual function and cognitive development may be impaired if the condition remains untreated or in cases of severe cretinism, which is rare. The rate of linear growth is retarded in this condition and always less than weight gain.
  27. 27. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 25 22/12/2017 76. Increased thyroid binding globulin level are found in ; A. pregnancy B. nephrotic syndrome C. acute hepatitis D. androgen therapy E. cirrhosis Ans ;AC TBG levels increase in pregnancy and in the newborn period, and with administration of estrogens (oral contraceptives , clofibrate therapy), perphenazine, and heroin , acute hepatitis & congenital excess (X linked dominant ) Decrease with androgens, anabolic steroids, glucocorticoids, and l-asparaginase, congenital deficiency, nephrotic syndrome , sever liver failure 77. The thyroid stimulating hormone ; A. is released from the hypothalamus B, secretion is inhibited by somatostatin C. activate cyclic adenosine monophosphate D. increase the uptake of iodide into the thyroid gland . E. increase the proteolysis of thyroglobuline in the thyroid follicle Ans; BCDE 78. A 5-month-old girl presented with history of constipation and delayed developmental milestones. She hadprolonged physiological jaundice On exam, she is hypoactive, has an open mouth with large tongue. Other systemic examinations are within normal.What is the next step in management? A) Checking T4 and TSH B ) Checking serum bilirubin C ) Doing CT scan of head D ) Follow up after 4 weeks Ans; A 79. Which one of the following options would not be expected in association with poorly controlled hypothyroidism in an 18 month old infant? A. High plasma TSH concentration. B. Delayed bone age. C. Umbilical hernia. D. Diarrhoea. E. delayed development milestones. Ans:-D Comments: High plasma TSH concentration with low Free Thyroxine level would occur. Thyroid hormone is a prerequisite for normal growth and cognitive /psychomotor development so bone age and developmental milestones would be delayed. Umbilical herniae are a feature. Constipation is a feature rather than diarrhoea. 80. Presenting features of hypothyroidism include A. deafness. B. menorrhagia. C. hirsutism.
  28. 28. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 26 22/12/2017 D. enlarged thyroid gland. E. osteoporosis. Ans:-ABCD Comments: Hirsutism is rarely reported in association with hypothyroidism although hair loss also features. Goitre is a frequent feature in both Hashimoto's thyroiditis and also iodine deficiency. Other presenting features include ataxia/neuronopathies particularly compression neuronopathies and the peaches and cream appearance due to hyper-betacarotinaemia. Cognitive impairment, macrocytic anaemia and pleural effusions also feature. 81. Primary hypothyroidism is associated with the following in childhood: A. Macrocytic anaemia. B. Alopecia areata. C. Cerebellar ataxia. D. Multiple serous effusions. E. Addison's disease. Ans:-ABDE Comments: Hypothyroidism has the following clinical features: • INFANTS: Feeding problems, prolonged jaundice, constipation, pale cold skin, course facies, large tongue, hoarse cry, occasional goitre, umbilical hernia, delayed development. • CHILDREN: Cold intolerance, dry skin, cold peripheries, bradycardia, dry thin hair, pale puffy eyes with loss of eyebrows, goitre, slow relaxing reflexes, constipation, short stature, delayed puberty, obesity, deteriorating school work, learning difficulties, hyperprolactanaemia. There is a known association with autoimmune diseases such as alopecia, vitiligo, pernicious anaemia, Addison's Disease. 82. juvenile or acquired hypothyroidism ; A. is most commonly due to autoimmune thyroiditis B. is an important cause of mental handicap C. causes of sever delay of skeletal maturation D. is more prevalent in children with Down syndrome E. is linked to familial thyroglobulin deficiency Ans ; ACD Acquired hypothyroidism is most commonly a result of chronic lymphocytic thyroiditis; 1.3% of children have evidence of autoimmune thyroid disease , children with Down, Turner, and Klinefelter syndromes and celiac disease or diabetes are at higher risk for associated autoimmune thyroid disease Hypothyroidism may be overt, but subclinical forms are more common, and periodic assessment of TSH levels is indicated . Deceleration of growth is usually the first clinical manifestation, schoolwork and grades usually do not suffer, even in severely hypothyroid children, Osseous maturation is delayed Adolescents typically have delayed puberty, whereas younger children may present with galactorrhea or pseudo precocious puberty. Galactorrhea is a result of increased TRH-stimulating prolactin secretion. The precocious puberty, characterized by breast development in girls and macro-orchidism in boys, is thought to be the result of abnormally high TSH concentrations binding to the follicle-stimulating hormone receptor with subsequent stimulation. 83. Feature of juvenile hypothyroidism include ;
  29. 29. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 27 22/12/2017 A. decrease sleep requirement B. increase hair growth. C. poor school performance D. tremor E. delayed ankle reflex Ans ; C E schoolwork and grades usually do not suffer , a slow relaxation component of deep tendon reflexes (best appreciated in the ankles). 84. Poorly controlled hypothyroidism in an 18 month old infant is associated with: A. High plasma TSH concentration. B. Delayed bone age. C. Umbilical hernia. D. Diarrhoea. E. Normal development milestones. Ans:-ABC Comments: High plasma TSH concentration with low Free Thyroxine level would occur. Thyroid hormone is a prerequisite for normal growth and cognitive /psychomotor development so bone age and developmental milestones would be delayed. Constipation is associated as are umbilical herniae. 85. Which of the following is associated with a high serum thyroxine concentration? A. Normal newborns. B. Hashimoto’s syndrome. C. Thyrotoxicosis. D. Nephrotic syndrome. E. Cystic fibrosis. Ans:-AC Comments: Shortly after delivery there is a rise in TSH thought to be a result of the abrupt change in environmental temperature and this returns to normal by 48h. The rise in TSH triggers a rise in thyroxine, which is in the hyperthyroid range by 24 hours. Hashimoto’s syndrome results in low serum thyroxine. Nephrotic syndrome results in a low thyroid binding globulin and reduces total serum thyroxine. Cystic fibrosis may result in reduction in thyroxine concentration as a result of the reduced TSH secretion, which occurs in ill patients. 86. Cretinism is characterised by which of the following? A. Delayed dentition. B. Incidence about 1:200. C. Paralytic ileus. D. Persistance of jaundice in neonate. E. Premature fusion of epiphyses. Ans:-ACD Cretinism is characterised by retarded bone age. The incidence of cretinism is about 1:5000. Other characteristics include: short stature protruding tongue broad flat nose
  30. 30. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 28 22/12/2017 widely set eyes sparse hair dry skin protuberant abdomen umbilical hernia. 87. it is true that hyperthyroidism ; A. in neonate can occur in infant of mother with both active and inactive hyperthyroidism B. in childhood secondary to Graves's disease isn't associated with thyroid goiter C. may result in polyuria and Nocturia. D. commonly an acute onset in childhood. E. that is treated medically will result in long term remission in 50% of children within 2 years . Ans ;AC The mothers of these infants have active Graves disease, Graves disease in remission or, rarely, hypothyroidism, and a history of lymphocytic thyroiditis. Symptoms of hyperthyroidism develop gradually; and diagnosis is 6–12 mo and may be longer in prepubertal children compared with adolescents. The earliest signs in children may be emotional disturbances accompanied by motor hyperactivity. a goiter is found in almost all patients. 88. Feature of Graves disease include ; A. inappropriate weight gain . B. association with HLA-DR3 . C. diarrhea. D. poor concentration. E. male predominance. Ans ;BCD About 5% of all patients with hyperthyroidism are younger than 15 yr of age The incidence is about five times higher in girls than in boys , Graves disease is associated with HLA-B8 and HLA-DR3 The earliest signs in children may be emotional disturbances accompanied by motor hyperactivity. The children become irritable, excitable, and cry easily , Tremor of the fingers can be noticed if the arm is extended. There may be a voracious appetite combined with loss of or no increase in weight , diarrhea Goiter is found in almost all patients. Exophthalmoses is noticeable in most patients but is usually mild skin is smooth and flushed, with excessive sweating , Muscular weakness is uncommon Tachycardia, palpitations, dyspnea, and cardiac enlargement and insufficiency Mitral regurgitation, probably resulting from papillary muscle dysfunction , systolic blood pressure and the pulse pressure are increased . Approximately half of the childhood cases will remit spontaneously within 2-4 years. Many will progress to become clinically hypothyroid 89. Maternal thyrotoxicosis A. may result in fetal tachycardia B. place the fetus at risk as the result of excessive placental transfer of free thyroxine C. is contraindication of the use of Thiouracil drugs ( carbimazole ) D. may result in neonatal thyrotoxicosis lasting 2-3 months E. is an absolute contraindication to breast feeding Ans ; AD
  31. 31. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 29 22/12/2017 Onset of neonatal hyperthyroidism usually begins prenatally and is present at birth The mothers of these infants have active Graves disease, Graves disease in remission or, rarely, hypothyroidism, and a history of lymphocytic thyroiditis. The condition is caused by transplacental passage of TRSAb, but the clinical onset, severity, and course may be modified by the concurrent presence of TRBAb and by the transplacental passage of antithyroid drugs taken by the mother The disorder usually remits spontaneously within 6–12 wk but may persist longer, depending on the levels of TRSAb. Mild asymptomatic hyperthyroxinemia also occurs Many of the infants are premature and appear to have intrauterine growth retardation. Most have goiters. The infant is extremely restless, irritable, and hyperactive, and appears anxious and unusually alert. Microcephaly and ventricular enlargement may be present. Atrial fibrillation is a rare complication . The eyes are opened widely and appear exophthalmic, weight loss occurs despite a ravenous appetite, hepatosplenomegaly increases, and jaundice may become manifested. Cardiac decompensation is common, and severe hypertension may occur. The infant may die if therapy is not instituted promptly. The serum level of T4 is markedly elevated and TSH is suppressed. Advanced bone age, frontal bossing with triangular facies, and cranial synostosis are common, especially in infants with persistent clinical manifestations of hyperthyroidism Advanced osseous maturation, microcephaly, and mental retardation occur when treatment is delayed 90. All of the following are characteristic of juvenile thyrotoxicosis except ; A. it occur almost exclusively as consequence of hyperfunctioning nodule B. onsets is insidious with increasing nervousness, palpitation & increased appetite C. rarely do children show Wt increase with the onset of the disease D. behavior abnormality & declining school performance is prominent . E. S/S are similar to those produced by hyperactive sympathetic nervous system . Ans ;A juvenile thyrotoxicosis ( Gravis disease ) occur almost exclusively as result of thyroid hyperplasia rather than hyperfunctioning nodule Hyperthyroidism occurs in ; Gravis disease McCune-Albright syndrome toxic uninodular goiter (Plummer diseas ) hyperfunctioning thyroid carcinoma thyrotoxicosis factitia subacute thyroiditis acute suppurative thyroiditis 91. Graves disease A. the peak incidence during adolescence B. atrial fibrillation is rare C. bone age is advanced . D. exophthalmous in the majority of the patient Ans ; ABCD. 92. Regarding hyperthyroidism in the adolescent: A. Usually resolves with 2 years of medical treatment. B. Radioiodine treatment should be avoided because of the risk of genetic damage and neoplasia.
  32. 32. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 30 22/12/2017 C. May present with heart failure. D. May be associated with increased stature and advanced bone age. E. May present with chronic diarrhoea. Ans:-CDE Comments: Neonatal hyperthyroidism is transient and is due to transferred thyroid stimulating immunoglobulins from mother. Juvenile hyperthyroidism is from Grave's Disease and is commonest in teenage girls. Symptoms include: • Systemic: anxiety, increased appetite, diarrhoea, weight loss; sweating, tremor, tachycardia, warm vasodilated peripheries; goitre; rapid growth with advanced bone age; behavioural problems. • Eye signs (not in variable): exophthalmos, ophthalmoplegia, lid retraction, lid lag. TREATMENT: • Medical: carbimazole, propylthiouracil. Betablockers can be used for symptomatic relief, but not on their own. 50% relapse after 2 years when treatment is stopped. • Surgical: sub-total thyroidectomy. • Radioiodine: not considered to result in neoplasia or genetic damage. Follow-up, and subsequent thyroxine therapy, is often needed. 93. Thyrotoxicosis in childhood: A. Is more common in girls. B. Is often associated with tall stature. C. Unlike adults is not caused by an auto-immune process. D. Is treated in the first instance with anti-thyroid drugs such as Carbimazole. E. Is usually associated with a high TSH level. Ans:-ABD Comments: Thyrotoxicosis has a female preponderance in all age groups. Thyrotoxicosis in early life may cause delayed sexual maturation, although physical development is normal and skeletal growth may be accelerated. Thyrotoxicosis in this age group is mostly due to grave’s disease. Anti thyroid drugs, are used initially and relapses can be treated with drugs or surgery. Radioactive iodine is generally not administered. TSH is suppressed. 94. A 14 yr old girl presents with poor growth and delayed puberty. She denies headaches or poor school performance. She is physically sluggish and has a small goiter. The most likely diagnosis is: A. Hashimoto thyroiditis . B. Graves disease . C. Congenital hypothyroidism D. Familial type II hyperlipidemia E. Pituitary prolactinoma Ans:-A Lymphocytic thyroiditis is the most common cause of thyroid disease in children and adolescents and accounts for many of the enlarged thyroids formerly designated "adolescent" or "simple" goiter. It is also the most common cause of acquired hypothyroidism, with or without goiter. The disorder is 2-4 times more common in girls than in boys. It can occur during the 1st 3 yr of life but becomes sharply more common after 6 yr of age and reaches a peak incidence during adolescence. The most common
  33. 33. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 31 22/12/2017 clinical manifestations are goiter and growth retardation. The goiter can appear insidiously and may be small or large. In most patients, the thyroid is diffusely enlarged, firm, and nontender. In about 30% of patients, the gland is lobular and can seem to be nodular. Most of the affected children are clinically euthyroid and asymptomatic; some may have symptoms of pressure in the neck, including difficulty swallowing and shortness of breath. Some children have clinical signs of hypothyroidism, but others who appear clinically euthyroid have laboratory evidence of hypothyroidism. A few children have manifestations suggesting hyperthyroidism, such as nervousness, irritability, increased sweating, and hyperactivity, but results of laboratory studies are not necessarily those of hyperthyroidism. 95. A 18 year-old girl presents with anxiety and palpitations. Her mother had been treated for an overactive thyroid gland having received radioiodine and was now on Thyroxine replacement therapy. On examination she had a pulse of 104 bpm with a fine tremor and lid lag. There was no goitre palpable. Investigations revealed: serum free T4 = 33 pmol/L (10-20) plasma thyroid stimulating hormone (TSH) < 0.05 (0.5-4.5) serum antithyroid peroxidase (anti TPO) titre = 40 IU/L (<50) . What is the most likely cause of her symptoms? A. factitious thyrotoxicosis. B. familial hyperthyroglobulinaemia. C. Hashitoxicosis. D. Graves’ disease. E. Riedel’s thyroiditis Ans:-D Comments: Although the lead-in might make you think that this patient could gain access to thyroxine and so a diagnosis of factitious hyperthyroidism is possible, in practice this is extremely unlikely. A strong family history of thyrotoxicosis is typical for Graves' disease and the absence of a goitre with the absence of TPO antibodies (found in 80% of Graves cases) again is compatible with a diagnosis of Graves. 96. A 12 year old girl presents with anxiety and weight loss. She is noted to have a fine tremor and pulse of 100 beat per minute. Thyroid function tests confirm thyrotoxicosis. Which one of the following statements is true of thyrotoxicosis in children. A. Is more common in males. B. Is often associated with short stature. C. Is usually not due to an auto-immune process. D. Is treated in the first instance with anti-thyroid drugs such as Carbimazole. E. Is usually associated with a high TSH level Ans:-D Comments: Thyrotoxicosis has a female preponderance in all age groups. Thyrotoxicosis in early life may cause delayed sexual maturation, although physical development is normal and skeletal growth may be accelerated. Thyrotoxicosis in this age group is mostly due to grave’s disease. Anti thyroid drugs, are used initially and relapses can be treated with drugs or surgery. Radioactive iodine is generally not administered. TSH is suppressed. ___________________________________________________________________________________ 97. The following are true of angiotensin II:
  34. 34. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 32 22/12/2017 A. It is 50 time more potent than angiotensin I as a renal arterial vasodilator. B. It inhibits aldosterone secretion. C. It reduces afterload in cardiac failure. D. Angiotensin I is converted to angiotensin II in the kidney. E. Secretion is increased by hypokalaemia. Ans:-All False Comments: Renin is produced by the juxtaglomerular apparatus of the kidney, and converts and alpha-2 globulin to angiotensin I. In the lung angiotensin I is activated to angiotensin II, which is 50 times more potent as a presser agent than noradrenaline. Angiotensin II acts directly on the adrenal cortex to stimulate secretion of aldosterone, a potent mineralocorticoid produced in the zona glomerulosa. Renin secretion is increased by Na depravation, and aldosterone acts at the distal tubule to control sodium reabsorption (and indirectly, water reabsorption). 98. Aldosterone ; A. secretion is stimulated by fall in serum Na B. is secreted in response to raise in BP C. deficiency is cause of hypokalemia D. act on the ascending limb of the loop of henle E. level are normal in pseudohypoaldosteronism Ans ; A DEFICIENCY OF ALDOSTERONE OCCUR 1 . adrenal hypoplasia 2 . inborn error of steroidogenesis 3 . Addison disease 4 . adrenoleukodystrophy 5. exogenous steroid withdrawal 6. destruction of adrenal gland ( hemorrhage , TB ) 7 . drugs that increase steroid metabolism Rifampicin Ketconazole Phenobarbitone Phenytoin Mineralocorticoids (primarily aldosterone in humans promote sodium retention and stimulate potassium excretion in the distal tubule. 99. Concerning 21 hydroxylase deficiency ; A. the gene defect is known B. hypertension is common C. raised serum 17 hydroxyprogesterone is characteristic D. plasma chloride is low in salt loser E. can present as precocious puberty in males Ans ; ACDE 100. In congenital adrenal hyperplasia due to 21 hydroxylase deficiency ; A. presentation with low ACTH B. the inheritance is autosomal dominant C. there is incomplete virilization of male genitalia D. antenatal diagnosis is possible for the 1st born . E. there is defect in mineralcorticoid biosynthesis in 50-75% of cases
  35. 35. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 33 22/12/2017 Ans ;E 101. The features that suggest diagnosis of congenital adrenal hyperplasia in female infant are ; A. collapse with hypernatremic dehydration B. labioscrotal fold fusion C. genital pigmentation D. delayed bone age E. hypertension Ans ; BCE 102. A 6 days old male infant was seen in A/E with history of poor feeding and vomiting. Mother was breast feeding and baby’s birth weight was 3.5 kg . Baby’s was born by normal vaginal delivery and APGAR score was 9 at 1 min and 10 at 5 min. Discharged home on day 2 after a normal post-natal examination. On examination baby’s current weight is 2.8kg and was noted to have normal male genitalia apart from hyperpigmented scrotum. Blood glucose was 2.8 in A/E and other observations are stable. Your initial investigations should include: A. Blood for electrolytes B. 17-hydroxyprogesterone. C. Renin, cortisol and ACTH. D. Renal USG. E. Karyotype. Ans:-ABCDE The clinical symptoms indicate a diagnosis of congenital adrenal hypoplasia. Salt-losing crisis usually occurs from day 5-14. *It is associated with hyponatraemia, hypochloremia and hyperkalaemia. *Hyperpigmentation is due to elevated ACTH. *Renal USG is to exclude the possibility of renal outflow obstruction causing a congenital salt-wasting nephropathy. 103. congenital adrenal hyperplasia present with ; A. hypospadias and impalpable gonads B. hypokalemia C. precocious puberty in boys D . palpable loin mass E. vomiting in second week of life Ans ;ACE 104. In congenital adrenal hyperplasia ; A. male infant may appear normal at birth B. testicular hypertrophy occurs C. female infant typically has clitoral hypertrophy & fusion labia minora D. infant may present with shock in early week of life E. ACTH is an effective treatment Ans; ACD 105. All of the following are characteristic of congenital adrenal hyperplasia except ; A. deficient production of cortisol start about 2 week after birth B. excessive secretion of adrenal androgen in the female fetus causes musculinization of the external genitalia C. acute adrenal crisis of salt losing form is due to absence of secretion of aldosterone. D. infant have poor appetite & fail to gain weight. E, excessive loss of Na result in sever H2O loss & dehydration.
  36. 36. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 34 22/12/2017 Ans ;A 106. Congenital adrenal hyperplasia is associated with: A. X- linked inheritance. B. Over-production of ACTH. C. A low serum potassium. D. Undescended testes. E. Infertility in later life. Ans:-BE Comments: Congenital Adrenal Hyperplasia has an autosomal recessive inheritance. Failure to synthesise cortisol by the adrenals leads to a feedback activation of ACTH production by the pituitary. Potassium retention occurs as a consequence of aldosterone deficiency. Undescended testes are not associated, however testicular adrenal rest tumours are associated. Undertreated patients may be infertile later due to the presence of high circulating androgens. 107. The following statements are true about congenital adrenal hyperplasia: A. It always presents shortly after birth. B. Boys more commonly present at an earlier age than girls. C. It is most frequently caused by 11-beta hydroxylase deficiency. D. It is commonly associated with genital pigmentation. E. It may be associated with hypertension Ans:-DE Comments: Congenital adrenal hyperplasia may present in teenagers with oligo/amenorrhoea and hirsuitism without significant virilisation and is termed late onset CAH. Girls present earlier because of virilisation and ambiguous genitalia, boys may present with precocious puberty. It is most commonly caused by 21 hydroxylase deficiency and genital pigmentation is due to high circulating ACTH 11 beta hydroxylase deficiency can cause virilisation with hypertension. 108. The following are features of congenital adrenal hypoplasia: A. Low renin levels. B. Exaggerated diurnal cortisol responses. C. Association with Duchenne Muscular Dystrophy. D. Association with vitiligo. E. Presentation with diarrhoea, vomiting and dehydration. Ans:-CE Comments: Hypoadrenalism usually presents in the neonatal period with increasing pigmentation, salt loss and cryptorchidism in males. The disorder is due to a mutation in the DAX0 gene, a new nuclear hormone receptor family, located on Xp21. Hypogonadotrophic hypogonadism (HHG) is caused by the same gene mutation, and the cryptorchidism is explained by this. The disorder is located very close to the Duchenne muscular dystrophy gene and the glycerol kinase gene, so these are associations.
  37. 37. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 35 22/12/2017 109. The following findings suggest a diagnosis of 21-hydroxylase deficiency rather than congenital adrenal hypoplasia: A. Advanced bone age. B. Salt loss in the neonatal period. C. Pubic hair development. D. Hyperpigmentation. E. Raised ACTH levels Ans:-AC Comments: Congenital adrenal hypoplasia is X-linked, although milder autosomal recessive forms exist. There is decreased production of cortisol, so ACTH levels are elevated. Salt loss in the neonatal period may occur, and there may be hyperpigmentation. Puberty does not occur, and there may be associated bilateral cryptorchidism, because of a contiguous gene defect (hypogonadotrophic hypergonadism). 21- Hydroxylase deficiency accounts for 95% of congenital adrenal hyperplasia. This results in a decreased production of cortisol and aldosterone. ACTH is secondarily raised. Females usually present with an intersex condition in the neonatal period. Boys are at greater risk from salt loss, which occurs in two thirds of cases. This can lead to severe dehydration in the neonatal period. If they are not salt losers, then they may present with advance bone age, and dissociation (penile and pubic hair development while testes remain infantile) in later childhood. 110. In congenital adrenal hyperplasia (CAH):- A. 21-hydroxylase deficiency is the commonest variety. B. virilisation may be prevented by glucocorticoid treatment. C. adrenal crisis may occur within a few days of birth. D. blood 17-hydroxyprogesterone concentrations are greatly increased. E. severe hypoglycaemia may occur. Ans:- ABCDE Comments: CAH is due to 21 hydroxylase deficiency in over 90% of cases. Early treatment (in vivo treatment with steroids for the mother is used) may prevent virilisation of the female fetus. Salt losing adrenal crisis is well recognised in the classic variety of the disease with severe hyponatraemia, hypotension and hypoglycaemia from birth onwards. 21 hydroxylase is one of the enzyles responsible for the conversion of 17 OHP to cortisol and aldosterone. Consequently this metabolite is found in excess in CAH. 111. A child aged 10 days has ambiguous genitalia. Which of the following may be causative:- A. if a buccal smear is chromatin negative there is a serious risk of an Addisonian crisis. B. a raised urinary output of pregnanetriol would confirm a diagnosis of congenital adrenal hyperplasia. C. the finding of the genotype 45 XO would reliably explain the anomaly. D. if testicles are present in the "labia" an acceptable explanation would be Klinefelter's syndrome. E. the most important factor in deciding the sex to which the child should be assigned is the genetic (chromosomal) sex ANs:-B Comments:
  38. 38. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 36 22/12/2017 If the buccal smear positive ie female then there would be at increased risk of salt crisis. Salt losers presenting in newborn period with crisis are more likely to be female. The commonest cause of ambiguous genitalia at birth is CAH, of which 95% are deficient in 21-hydroxylase. Less common enzyme defects involve 11B hydroxylase, and 3B hydroxysteroid dehydrogenase. About 2/3 of 21-hydroxylase are salt losers, and present with an hypoadrenal crisis. There is normal male genitalia in 47 XXY – Klinefelter’s and Turner’s - XO. In intersex states, the assignation of sex is not totally based on the karyotype. 112. A 14 day old boy is admitted with collapse. She was born at 38+2/40 weighing 3.47kg to a healthy Caucasian mother. Pregnancy and delivery had been uncomplicated. Following discharge she had failed to gain weight, and began vomiting 3 days ago. This had persisted and worsened. Over the past 2 days the nappies had been wet twice a day. On examination temperature 36.2°C(tympanic), HR 160/min (thready pulses), RR 40/min. No murmur, chest clinically clear. Abdomen soft with no organomegaly. O2 saturations 85% in air. Blood tests show: Na= 127 mmol/l, K= 5.8 mmol/l, Urea= 13.7 mmol/l, Cratinine= 74 , What is the most likely diagnosis? A. Congenital adrenal hyperplasia. B. Congenital heart disease. C. Inborn errors of metabolism. D. Sepsis. Ans:-A Comments: The picture is one of shock in a child who has become progressively dehydrated. Sepsis and congenital heart disease are possible, but there is nothing specific to point in these directions. The electrolytes make the likely diagnosis salt-losing congenital adrenal hyperplasia. 113. Congenital adrenal hyperplasia due to 21 hydroxylase deficiency: A. Causes testicular enlargement. B. Results in delayed fusion of epiphyses. C. Produces increased aldosterone secretion. D. Has an autosomal recessive inheritance. E. Is more easily diagnosed in boys than girls. Ans:-D Comments: The condition causes virilisation in the female (male secondary sexual characteristics e.g. clitoromegaly, ambiguous genitalia) and in males sexual development may be entirely normal or precocious puberty develops. Delayed epiphyseal fusion is not a feature. Aldosterone deficiency causes salt wasting in this condition. The disease has an autosomal recessive inheritance. The disease is far more easily diagnosed in females who develop abnormal genitalia, than males who may have no clinical signs. 114. A 5 yr old boy presents with pubic hair development. He is tall and has increased pigmentation of his genitalia and phallic enlargement. Blood pressure is 130/90 mm Hg. Measurement of which of the following hormones would be most likely to be diagnostic? A. Testosterone. B. 17-Hydroxyprogesterone.
  39. 39. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 37 22/12/2017 C. 11-Deoxycortisol. D. Aldosterone. E. Deoxycorticosterone Ans:-C 11β-Hydroxylase deficiency accounts for approximately 5% of cases of adrenal hyperplasia; its incidence has been estimated as 1/250,000 to 1/100,000. Although cortisol is not synthesized efficiently, aldosterone synthetic capacity is normal, and some corticosterone is synthesized from progesterone by the intact aldosterone synthase enzyme. Thus, it is unusual for patients to manifest signs of adrenal insufficiency such as hypotension, hypoglycemia, hyponatremia, and hyperkalemia. Approximately 65% of patients become hypertensive, although this can take several years to develop. Hypertension is probably a consequence of elevated levels of deoxycorticosterone, which has mineralocorticoid activity. Infants may transiently develop signs of mineralocorticoid deficiency after treatment with hydrocortisone is instituted. This is presumably due to sudden suppression of deoxycorticosterone secretion in a patient with atrophy of the zona glomerulosa caused by chronic suppression of renin activity. All signs and symptoms of androgen excess that are found in 21-hydroxylase deficiency may also occur in 11-hydroxylase deficiency. Plasma levels of 11-deoxycortisol and deoxycorticosterone are elevated. 115. 2 week old male child is brought to casualty by his concerned parents with diarrhoea and vomiting. He is the first child of a young couple. Examination reveals few features besides obvious dehydration. He is noted to have a penile length of 3.5cms. Which of the following is the most appropriate inital treatment for this patient? A. Cow's milk allergy is the most likely diagnosis. B. gluten-enteropathy should be excluded. C. Requires urgent treatment with oral steroids. D. Requires urgent treatment with IV normal saline. E. Rota virus gastroenteritis is the most likely diagnosis. Ans:-D Comments: The history suggests a diagnosis of classical congenital adrenal hyperplasia which is commonly due to 21 hydroxylase deficiency. A variable presentation is typical but neonatal presentations include salt losing crisis, penile development in the male virilisation and ambiguous genitialia in females. Patients should initially be resuscitated with fluid, usually saline and if suspicious, urgent biochemistry requested for cortisol, 17OHP etc prior to administration of intravenous steroids. 116. A 7-day-old boy is admitted to a hospital for evaluation of vomiting and dehydration. Physical examination is otherwise normal except for min-imal hyperpigmentation of the nipples. Serum sodium and potassium con-centrations are 120 mEq/L and 9 mEq/L (without hemolysis), respectively; serum glucose is 40 mg/dL. Which of the following is the most likely diagnosis? A. Pyloric stenosis. B. Congenital adrenal hyperplasia C. Secondary hypothyroidism. D. Panhypopituitarism. E. Hyperaldosteronism Ans:-B
  40. 40. ABDULRAHMAN BASHIR CHILDREN HOSPITAL - BENGHAZI 38 22/12/2017 Salt-losing congenital adrenal hyperplasia (adrenogenital syndrome, 21-hydroxylase deficiency) usually manifests during the first 5 to 15 days of life as anorexia, vomiting, diarrhea, and dehydration. Hypoglycemia can also occur. Affected infants can have increased pigmentation, and female infants show evidence of virilization, that is, ambiguous external genitalia. Hyponatremia, hyperkalemia, and urinary sodium wasting are the usual laboratory findings. Death can occur if the diagnosis is missed and appropriate treatment is not instituted. Although adrenal aplasia, an extremely rare disorder, presents a similar clinical picture, it has an earlier onset than adrenal hyperplasia, and virilization does not occur. In classic 21-hydroxylase deficiency, serum levels of 17-hydroxyprogesterone are markedly elevated beyond 3 days of life (in the first 3 days of life they can normally be high). Blood cortisol levels are usually low in salt-losing forms of the disease. Pyloric stenosis seems unlikely in this infant in that the vomiting with this disease usually begins after the third week of life. Hypothyroidism would present as a lethargic, poor-feeding infant with delayed reflexes, persistent jaundice, and hypotonia. Hyperaldosteronism would be expected to cause decreased potassium, not increased levels. Panhypopituitarism usually presents with apnea, cyanosis, or severe hypoglycemia. 117. 16 year old girl is brought by her mother to her physician. Her mother complains that her daughter's breasts have failed to develop at all. The girl has not had her first menstruation either. On inspection she is noted to be short and obese and is found to have abundant pubic and axillary hair and a receding hairline. On investigation she is found to have a 21- hydroxylase deficiency. The most likely diagnosis is a) constitutional delay b) hypothyroidism c) Hand-Schuller-Christian Disease d) congenital adrenal hyperplasia e) craniopharyngioma Correct answer: D EXPLANATION The manifestations of congenital adrenal hyperplasia, because of excess androgens, may be similar to Cushing's syndrome. Congenital adrenal hyperplasia is generally diagnosed prior to puberty, and heterosexual precocious pseudopuberty is typical. However, if the defect is mild and changes to the external genitalia are minimal, masculinization may occur at the expected age of puberty. This attenuated or nonclassic form of 21- hydroxylase deficiency seems to occur in families with a strong family history of hirsutism. Affected girls generally have some defeminization with flattening of the breasts, severe hirsutism, relatively short stature, and obesity. 118. A child is diagnosed with congenital adrenal hyperplasia. Which of the following statements correctly applies to his condition. A. It has an X-linked inheritance. B. There is over-production of cortisol. C. Hypokalaemia occurs. D. Undescended testes is associated.

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pediatric MCQ on endocrine branch

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