Disorders of Sex Development

Question 1

most common cause of 46 XX DSD (excessive fetal androgen production)

Answer 1

21-hydroxylase def

Question 2

46 XX DSD = excessive ___

Answer 2

fetal androgen production

Question 3

patients with ovotesticular DSD are usually

Answer 3

46XX

Question 4

defective functions in 46 XY DSD (4)

Answer 4

Defect in testicular differentiation

Defect in sertoli cell function > inadequate MIS + persistence of mullerian ducts

Defect in leydig cell function - testoterone sythesis defect, LH/HCG response defect (needed for androgen production)

defect in function of androgen target tissue (androgen insensitivity, defect in DHT synth)

Question 5

Congenital adrenal hyperplasia forms in 46 XY DSD (3)

Answer 5

3 beta hydroxysteroid dehydrogenase deficiency

17-hydroxylase / 17,20 lyase combined deficiency

side chain cleavage deficiency

Question 6

consider DSD when

Answer 6

**Genitalia do no appear 100% normal **

bilateral nonpalpable gonads

severe hypospadias, esp with nonpalpable gonads

clitoromegaly or microphallus

posterior fusion of vaginal opening / undervirilized scrotum

Question 7

genetics Androgen insensitivity syndrome

most common presentations

Answer 7

X linked recessive, 46, XY

CAIS: female adolescent with pirmary amenorrhea and breat, no pubic hair (or female with tests discovered in inguinal hernia)

PAIS: highly variable (ambiguous genitalia OR phenotypically normal male with infertility)

Question 8

karyotypes for ovotesticular DSD

Answer 8

46XX mot common

46 XY

46XY/46XX

Question 9

genitalia and gonads in ovotesticular DSD

Answer 9

Ovarian and testicular tissue present (bilateral ovotestes or one of each)

external genitalia varry

internal anatomy parallels ipsilateral gonad

Question 10

androgen biosynthetic defects

Answer 10

low andostenedione production (rare forms of CAH with adrenal and gonadal enzyme defects)

17-ketosteroid reductase def (17-KR) (testis)

5-alpha reductase (5a-Red) def (skin)

Question 11

genetic and mutation 5-alpha reductase def

morphologic impact

Answer 11

46XY karyotype, autosomal recessive

(impaired conversion of T to DHT

DHT critizal for virilization prior to birth, but T is critical at pubert

(T surge at puberty > dramatic virilization)

Question 12

treatment for CAH - 212hydroxylase deficiency

Answer 12

cortisol replacement to suppress ACTH and reduce adrenal androgens

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

Answer 16