Newborn Disorders of Sexual Development

Question 1

Which gene determines the gonadal sex

Question 2

Role of Leydig and sertoli cells in male fetus

Answer 2

leydig: produces testosterone to maintain the Wolffian strucures

Sertoli cells: produced MIF to cause regression of mullerian sturctures.

Question 3

how is DSD classified (3 classes)

Answer 3

1. sex chromosome DSD; like Turners, Klinefelters
2. Undervirilized. XY – disorders of gonadal development, disorders of androgen synthesis
3. virilized XX: disorders of androgen excess or of gonadal development

Question 4

Prader 0 to prader 5

Answer 4

prader 0= totally female

prader 5= totally mal

Question 5

2 main causes of endogenous fetal androgen that can cause virilized XX

Answer 5

Congenital adrenal hyperplasia (usually 21 hydroxylase deficinecy)

Ovarian or adrenal neoplasm (rare)

• non endogenous/transplacental maternal androgen can also cause virilized XX in a child

Question 6

Answer 6

Question 7

Inadequate Androgen Production causes that result in an undervirilized XY DSD

Answer 7

1. LH or BHCG receptor defect which prevents testosterone release from Leydig cell (therefore, no preservation of Wolfian Duct)
2. leydig cell hypoplasia/problem
3. Testicular dysgenesis/gonadal dysgenesis
4. anorchia (testicular regression syndrome)

Question 8

Answer 8

Question 9

Answer 9

Question 10

androgen receptor defects (XY) leads to __ ___ syndrome

Answer 10

testicular feminization syndrome.

• there is a defect in the receptor so that DHT cannot bind. You thus cannot release actual testosterone and hten you do not externally masculinize. can cause female external genitals despite having testes.

will results in primary amenorrhea

Question 11

AMH defiency in males will result in :

Answer 11

NO MULLERIAN DUCT REGRESSION. Will thus have potentially fallopian tubes and uterus, but the LEYDIG CELLS ARE NOT COMPROMISED so you will also have testes.

Question 12

fill out the table for tuners syndrome

Answer 12

Question 13

Fill out the table for Swyer syndrome

Answer 13

they are karyotypically XY with a defective SRy gene– so they can’t actually really masculinize at all– will look phenotypically female.

Question 14

test you must run when a baby is born with ambiguous genitalia

Answer 14

adrenal function tests– cortisol etc. Gotta make sure there is not an adrenal crisis (ex/ CAH leading to low cortisol and high ACTH, causing incrased virilization in female baby)– the low cortisol in this case can cause an adrenal emergency

Question 15

T/f id you have androgen insensitivity, giving testerone will be therapeutic

Answer 15

false. androgen insensitivity means that it doesn’t have any receptor for dihydroytestosterone. Testerone turns into DHT (via 5 alpha reductase) so even if you give DHT’s precursor, it’ll just turn into something that can’t be used.

Question 16