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4 Female Male Chromosomal Intersex

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4 Female Male Chromosomal Intersex

Part 4 of "Science & Sexuality." What exactly is a female? a male? an intersex person? Some kinds of intersex people are chromosomal variants. What can we learn about sexual identity and sexual orientation from sex chromosomal variants? Who is Milton Diamond? John Money?

Part 4 of "Science & Sexuality." What exactly is a female? a male? an intersex person? Some kinds of intersex people are chromosomal variants. What can we learn about sexual identity and sexual orientation from sex chromosomal variants? Who is Milton Diamond? John Money?

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4 Female Male Chromosomal Intersex

  1. 1. What Is a Female? A Male? <ul><li>Primary sex characteristic </li></ul><ul><ul><li>Type of gonads </li></ul></ul><ul><ul><ul><li>Female gonad is ovary – produces eggs </li></ul></ul></ul><ul><ul><ul><li>Male gonad is testis – produces sperm </li></ul></ul></ul><ul><ul><li>Develop in fetus </li></ul></ul><ul><ul><li>Testosterone & its derivatives are “directional” </li></ul></ul><ul><li>Secondary sex characteristics </li></ul><ul><ul><li>Produced by gonadal hormones </li></ul></ul><ul><ul><ul><li>Androgens </li></ul></ul></ul><ul><ul><ul><li>Estrogens </li></ul></ul></ul><ul><ul><li>Develop during puberty </li></ul></ul><ul><ul><li>Hormones are “activational” </li></ul></ul>
  2. 2. Sex Has Many Levels <ul><li>Genetic Sex - Chromosomes </li></ul><ul><li>Gonadal Sex – Ovaries or Testis </li></ul><ul><li>Somatic Sex – Body anatomy/physiology </li></ul><ul><li>Psychological Sex - Sexual identity </li></ul><ul><li>and then there is </li></ul><ul><li>Sexual orientation </li></ul>
  3. 3. Intersexuality <ul><li>Incidence: 1.7%*- 2.5% </li></ul><ul><li>Intersexual people are as natural as the rest of us </li></ul><ul><li>They are nature’s experiments to a physiologist – providing information about sexual development </li></ul><ul><li>Only in recent years have we been able to track intersexual people over their lifetime and find out about their sexual identity and orientation </li></ul><ul><li>They illustrate how no definition of female or male is always “satisfying” </li></ul><ul><li>* Fausto-Sterling, Anne. SEXING THE BODY: GENDER POLITICS AND THE CONSTRUCTION OF SEXUALITY. Basic Books (2000) </li></ul>
  4. 4. Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)
  5. 5. How to Treat a Newborn With Ambiguous Genitalia or Mutilated Penis?
  6. 6. John Money Psychologist <ul><li>Psychosexual &quot;neutrality-at-birth&quot; theory </li></ul><ul><ul><li>Postulate 1: Individuals are psychosexually neutral at birth </li></ul></ul><ul><ul><li>Postulate 2: Healthy psychosexual development is intimately related to the appearance of the genitals </li></ul></ul>
  7. 7. Milton Diamond Biologist <ul><li>“ Sexuality-at-birth&quot; theory </li></ul><ul><ul><li>Theory of psychosexual predisposition </li></ul></ul><ul><ul><li>Inherent sexuality provides a built-in &quot;bias&quot; with which the individual interacts with his environment </li></ul></ul><ul><ul><li>Prenatal genetic and hormonal influences predispose at birth to a male or female gender orientation </li></ul></ul><ul><ul><li>Sexual behavior of an individual, and thus gender role, are not neutral and without initial direction at birth </li></ul></ul><ul><li>Diamond challenges Money </li></ul><ul><li>Diamond M. A Critical Evaluation Of The Ontogeny Of Human Sexual Behavior. QUARTERLY REVIEW OF BIOLOGY, 40: 147–175 (1965) </li></ul><ul><li>The John / Joan case </li></ul><ul><li>Diamond, Milton. And Sigmundson, H. Keith. Sex Reassignment at Birth: A Long Term Review and Clinical Implications. ARCHIVES OF PEDIATRIC & ADOLESCENT MEDICINE, 151: 298-304 (1997) </li></ul><ul><li>Money’s view is now discredited! </li></ul>
  8. 8. Chromosomal Variants of Sexes 1/500 of the population have a karyotype other than XX or XY. Intersex Support Group International (1999-2001) Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)
  9. 9. Variations of Genetic Sexes <ul><li>Nondisjunction of chromosomes </li></ul><ul><ul><li>XO Female (Turner Female) </li></ul></ul><ul><ul><li>XXX Female (Superfemale) </li></ul></ul><ul><ul><li>XXY, XXXY etc. Male (Klinefelter Male) </li></ul></ul><ul><ul><li>XYY Male (Jacob’s Syndrome) </li></ul></ul><ul><li>Translocation of SRY gene from Y to X chromosome </li></ul><ul><ul><li>XY Female (Swyer syndrome): absence or mutation of SRY on Y produces females with gonadal dysgenesis </li></ul></ul><ul><ul><li>XX Male (XX Male Syndrome): SRY gene in one or both X chromosomes, produces infertile males </li></ul></ul>
  10. 10. Turner’s Syndrome <ul><li>Karyotype is 44 autosomes plus XO </li></ul><ul><li>Ovarian agenesis or gonadal dysgenesis </li></ul><ul><ul><li>Gonads rudimentary or absent </li></ul></ul><ul><ul><li>Female external genitalia </li></ul></ul><ul><ul><li>Short stature, other congenital abnormalities </li></ul></ul><ul><ul><li>No maturation at puberty </li></ul></ul>Luria, Z., Friedman, S., and Rose, M.D. HUMAN SEXUALITY. New York: John Wiley & Sons (1987)
  11. 11. Turner’s  Syndrome Forbes, C.D. and Jackson, W.F. A COLOUR ATLAS AND TEXT OF CLINICAL MEDICINE. England: Mosby-Wolfe (1993)
  12. 12. Klinefelter Syndrome <ul><li>Karyotype 47XXY </li></ul><ul><li>Most common sex chromosome disorder (1 or 2 cases/1000) </li></ul><ul><li>Male phenotype </li></ul><ul><li>Hypogonadism </li></ul><ul><li>Seminiferous tubule dysgenesis </li></ul><ul><ul><li>Reduced or absent spermatogenesis </li></ul></ul><ul><ul><li>Variability in presentation is related mainly to the timing and amount of androgen deficiency </li></ul></ul><ul><ul><li>Increased FSH levels (indicates low inhibin B from Sertoli cells) </li></ul></ul><ul><ul><li>The more supernumerary sex chromosomes that exist, the more likely are detrimental physical and mental findings </li></ul></ul><ul><ul><li>Cryptorchidism 3X more frequent </li></ul></ul><ul><ul><li>Taller, greater leg growth ( 5 and 8 years) </li></ul></ul><ul><ul><li>Tendency for central obesity </li></ul></ul><ul><ul><li>Minority born with small penises; testosterone cream caused penis growth; however, normal size penis in only 77% by end of puberty; in contrast, testes normal size at birth but fail to grow normally </li></ul></ul><ul><ul><li>Gynecomastia 30% to 90% of cases </li></ul></ul><ul><ul><li>May have diminished body and facial hair, female pubic hair pattern, small phallus, poor muscular development, and progressive disproportion in leg and body length, feminine fat distribution </li></ul></ul><ul><ul><li>Fertility becomes increasingly doubtful as age advances; however, before infertility is predicted, sperm analysis is required because paternity has been documented </li></ul></ul>Forbes, C.D. and Jackson, W.F. A COLOUR ATLAS AND TEXT OF CLINICAL MEDICINE. England: Mosby-Wolfe (1993)
  13. 13. Klinefelter Syndrome & Gender Expression <ul><li>Infrequently discussed in medical descriptions of KS are individuals’ concerns with gender expressions and feelings </li></ul><ul><li>An unknown percentage of persons who have KS experience androgynous or feminine feelings that can develop at an early age </li></ul><ul><li>Some people who have KS consider themselves to be transgendered , others intersexed, and others transsexual; in one study, investigators concluded that all of their KS patients viewed their personalities as dual male and female </li></ul><ul><ul><li>A host of investigators similarly reported cases of men who had KS who transitioned to live as women or who harbored aspects of gender dysphoria </li></ul></ul><ul><ul><li>Carolyn Cossey, a “James Bond girl,” was raised as boy, but changed to live as a girl at young age, and became a famous model; her karyotype was found to be XXXY </li></ul></ul>
  14. 14. KS Subjects Are Gynephilic! <ul><li>KS subjects are gynephilic!  ”Homosexuality” among KS males was not found or the prevalence was not any different from that seen in the general population ( Shirley Ratcli ff e Arch Dis Child 1999; 80 :192–195) </li></ul><ul><li>Note: This indicates that sexual orientation region(s) of brain have been “altered.” Significantly, XXY fetal prenatal and postnatal testosterone levels do not differ from XY controls – so testosterone is available to “alter” hypothalamic and other brain regions during development of KS brain </li></ul>
  15. 15. Comparison of XYYs and XXYs Sex Roles <ul><li>Similarities far outweigh the differences except for sex roles </li></ul><ul><li>XXY has more problems with masculine role </li></ul><ul><ul><li>Appear less masculine </li></ul></ul><ul><ul><li>More submissive and dependent </li></ul></ul><ul><ul><li>Drawings show less sex-differentiation </li></ul></ul><ul><ul><li>Ratcliffe, Shirley. Long Term Outcome In Children Of Sex Chromosome Abnormalities. ARCH DIS CHILD; 80:192–195 (1999) </li></ul></ul>
  16. 16. Why Do Many of These KS “Men” Identify As Androgynous or Women? <ul><li>My tentative answer </li></ul><ul><li>Research evidence for expression of genes on sex chromosomes in early brain development </li></ul><ul><li>XX and XY embryonic rodent brains develop differently before gonads develop (so hormone influence is not a factor) </li></ul><ul><li>Dewing, P., Shi, T., Horvath S., and Vilain, E. Sexually Dimorphic Gene Expression in Mouse Brain Precedes Gonadal Differentiation. MOLECULAR BRAIN RESEARCH, 118: 82-90 (2003) </li></ul><ul><li>Carruth, Laura L., Reisert, Ingrid, and Arnold, Arthur P. Sex Chromosome Genes Directly Affect Brain Sexual Differentiation. NATURE NEUROSCIENCE, 5: 933-934 (2002) </li></ul>

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