Klinefelter syndrome is a genetic condition where males are born with an extra X chromosome, resulting in XXY chromosomes instead of the typical XY. It was first described in 1942 and causes issues like infertility, low testosterone, and larger breasts. The condition occurs in about 1 in 1000 males and is diagnosed through hormone testing and chromosome analysis. While there is no cure, treatments can help manage symptoms like low muscle tone, delayed puberty, and small testes through testosterone therapy and other interventions.

1. Klinefelter
INTRODUCTION
Klinefelter syndrome is a genetic condition in which a boy is born with an extra X chromosome.
Instead of the typical XY chromosomes in men, they have XXY, so this condition is sometimes
called XXY syndrome.
Men with Klinefelter usually don’t know they have it until they run into problems trying to have
a child. There’s no cure, but it can be treated.
HISTORY
The syndrome was named after American endocrinologist Harry Klinefelter, who in 1942
worked with Fuller Albright and E. C. Reifenstein at Massachusetts General Hospital in Boston,
Massachusetts, and first described it in the same year. The account given by Klinefelter came to
be known as Klinefelter syndrome as his name appeared first on the published paper, and
seminiferous tubule dysgenesis was no longer used. Considering the names of all three
researchers, it is sometimes also called Klinefelter–Reifenstein–Albright syndrome In 1956 it
was discovered that Klinefelter syndrome resulted from an extra chromosome. Plunkett and Barr
found the sex chromatin body in cell nuclei of the body. This was further clarified as XXY in
1959 by Patricia Jacobs and John Anderson Strong. The first published report of a man with a
47,XXY karyotype was by Patricia Jacobs and John Strong at Western General Hospital in
Edinburgh, Scotland, in 1959. This karyotype was found in a 24-year-old man who had signs of
KS. Jacobs described her discovery of this first reported human or mammalian chromosome
aneuploidy in her 1981 William Allan Memorial Award address.
EPIDEMIOLOGY
This syndrome, evenly distributed in all ethnic groups, has a prevalence of one to two per every
1000 males in the general population it is estimated that only 25% of the individuals with
Klinefelter syndrome are diagnosed throughout their lives. 3.1% of infertile males have
Klinefelter syndrome. The syndrome is also the main cause of male hypogonadism.
CAUSES
In this condition get the extra X chromosome by chance. Either the egg or the sperm that came
together to create an extra X chromosome. Older women have a slightly higher chance of having
a boy with XXY syndrome, but the chance is small.
Men with Klinefelter may have:
 An extra X chromosome in every cell, which is the most common
 An extra X chromosome in only some cells, called mosaic Klinefelter, in which you don’t
have as many symptoms
 More than one extra X chromosome, which is very rare and more severe

2. CLINICAL FEATURES
Babies:
 Hernia
 More quiet than usual
 Slower to learn to sit up, crawl, and talk
 Testicles that haven’t dropped into the scrotum
 Weaker muscles
Children:
 A hard time making friends and talking about feelings
 Low energy levels
 Problems learning to read, write, and do math
 Shyness and low confidence
Teenagers:
 Larger breasts than normal
 Less facial and body hair, and it comes in later
 Less muscle tone, and muscles grow slower than usual
 Longer arms and legs, wider hips, and a shorter torso than other boys their age
 Puberty never comes, comes later, or doesn’t quite finish
 Small penis and small, firm testicles
 Taller than usual for the family
Adults:
 Infertility (can’t have children because they can’t make enough sperm)
 Low sex drive
 Low testosterone levels
 Problems getting or keeping an erection

3. DIAGNOSIS
1- History Collection
2- Physical Examination
3- Hormone testing. Blood or urine samples can reveal abnormal hormone levels that are a
sign of Klinefelter syndrome.
4- Chromosome analysis. Also called karyotype analysis, this test is used to confirm a
diagnosis of Klinefelter syndrome. A blood sample is sent to the lab to check the shape
and number of chromosomes.
TREATMENTS
There's no cure for Klinefelter syndrome, but some of the problems associated with the condition
can be treated if necessary.Possible treatments include:
 Testosterone replacement therapy -worksbyincreasingaboy's testosteronelevelsintothe
normal range.Additional testosterone canhelpaboywithklinefeltersyndrome developbigger
musclesanda deepervoice,aswell aspromote growthof the penisandfacial andbodyhair. It
can alsohelpimprove bone densityandreduce the growthof a boy'sbreasts. Testosterone
therapycannotincrease the size of a boy'stesticlesorpreventorreverse infertility.
 Speech and language therapy during childhood to help with speech development
 Educational and behavioural support at school to help with any learning difficulties or
behaviour problems
 occupational therapy to help with any co-ordination problems associated with dyspraxia
 physiotherapy to help build muscle and increase strength
 Psychological support for any mental health issues
 fertility treatment – options include artificial insemination using donor sperm or
possibly intracytoplasmic sperm injection (icsi), where sperm removed during a small
operation are used to fertilise an egg in a laboratory
 breast reduction surgery to remove excess breast tissue