Sex Chromosome Disorders Of Sexual Development

Front 1

Klinefelter syndrome

-Male, XXY, 1:850

Back 1

Klinfelter:

-Testicular atrophy, eunuchoid body shape
-Tall, long extremities, gynecomastia, female hair distribution.

-May present with developmental delay

-Presence of inactivated X chromosome (Barr body)

-Common cause of hypogonadism seen in infertility work-up.

-Dysgenesis of seminiferous tubules --> decreased inhibin --> increased FSH

-Abnormal Leydig cell function --> decreased testosterone --> increased LH --> increased estrogen

Front 2

Turner Syndrome
-Female, XO

"Hugs and kisses from Tina Turner"

Back 2

-Short stature if untreated

-Ovarian dysgenesis (streak ovary), shield chest, bicuspid aortic valve, pre-ductal coarction (femoral pulse lower than brachial pulse, notched ribs)

-lymphatic defects -- result in webbed neck or cystic hygroma (lymphatic cyst), lymphedema in feet/hands

-horseshoe kidney

*Most common cause of 1º amenorrhea

-no Barr body

-Menopause before menarche
-Decreased estrogen leads to increased LH and FSH
-Can be due to mitotic or meiotic error
-Can be complete monosomy (45,XO) or mosaicism (e.g, 45,XO/46,XX)

-Pregnancy is possible in some cases of Turner syndrome: oocyte donation, exogenous estradiol-17beta, progesterone.

Front 3

Double Y males
-male, XYY, 1:1000

Back 3

Phenotypically normal, very tall

-severe acne, antisocial behavior (in 1-2% of XYY males)

-normal fertility

-small percentage of XYY males diagnosed with autism spectrum disorders

Front 4

True hermaphroditism
-46,XX or 47,XXY

Back 4

Also called ovotesticular disorder of sex development

-Both ovary and testicular tissue present (ovotestis), ambiguous genitalia

-True hermaphroditism is very rare