Abnormal reproductive development

Question 1

In male fetuses, ______ causes the undifferentiated fetal gonad to develop into testes

Answer 1

SRY gene on Y chromosome

absence of SRY in females- gonad develops into ovaries

Question 2

The fetal testes secrete _____ and _____

Answer 2

testosterone

Question 3

Contrast the effects of AMH vs testosterone in male fetuses

Answer 3

AMH causes regression of the Mullerian duct

testosterone promotes Wolffian duct differentiation

Question 4

Describe early reproductive tract development in female fetuses

Answer 4

• absence of testosterone causes Wolffian duct regression

- lack of AMH allows for Mullerian duct differentiation into fallopian tubes, uterus, upper 2/3 of vagina

Question 5

In the absence of ___________, the genital tubercle becomes the clitoris, the urogenital sinus remains open to form the labia minora, the labioscrotal folds form the labia majora, and the urogenital sinus becomes the urethra and lower vagina.

Answer 5

dihydrotestosterone

Question 6

List three basic causes of sexual ambiguity

Answer 6

• Inappropriate virilization of a genetic female due to exposure to excess androgens.
• Under-masculinization of a genetic male due to reduced androgen production or impaired androgen responsiveness of target tissues.
• Presence of both ovarian and testicular tissue.

Question 7

In female fetuses, the absence of SRY gene and expression of ______ gene causes the undifferentiated gonad to form an ovary

Answer 7

FOXL2

Question 8

_______ is caused by defective migration of the GnRH containing neurons from the olfactory nasal epithelium to the hypothalamus

Answer 8

Kallmann’s Syndrome

usually KAL1, KAL2 genes

Question 9

List key distinguishing features of Kallmann’s syndrome in females

Answer 9

Ovarian dysfunction from hypothalamic source

• low LH/FSH
• absence of estrogen production
• delayed puberty, amenorrhea
• ansomnia

Question 10

In ______, amenorrhea occurs because the ovaries are replaced with fibrous tissue and do not produce sufficient estrogen

Answer 10

gonadal dysgenesis

Question 11

In all causes of gonadal dysgenesis, FSH levels are (high/low)

Answer 11

high- absence of estrogens from ovaries= no negative feedback of estrogen on FSH

Question 12

What is the most common cause of gonadal dysgenesis?

Answer 12

Turner syndrome

Question 13

What treatment is necessary in cases of gonadal dysgenesis with 46, XY karyotype?

Answer 13

gonadectomy- Y chromosome gives higher risk of gonadal tumors such as gonadoblastoma

Question 14

List key features of Mullerian agenesis?

Answer 14

female phenotype
absence of uterus
ovaries are present
lower 1/3 of vagina is developed (urogenital sinus origin) but upper 2/3 is missing (Mullerian duct origin)
hormone levels normal
amenorrhea

Question 15

_________ and ________ are characterized by cyclic pelvic pain and a perirectal mass from sequestration of blood in the vagina (hematocolpos).

Answer 15

Transverse vaginal septum, imperforate hymen

Question 16

What are the expected hormone levels in anatomic abnormalities of the female reproductive tract (transverse vaginal septum, Mullerian agenesis)

Answer 16

normal LH, FSH, estradiol for pubertal stage
normal pubertal development- breast development, pubic hair
primary amenorrhea

Question 17

List key findings in androgen insensitivity syndrome

Answer 17

• 46, XY with female phenotype due to lack of sensitivity to androgens- bilateral undescended testes
• blind vaginal pouch, absent Mullerian- derived structures
• breast development- aromatization to estrogen at breast
• testosterone levels in normal range for adult males
• PUBIC HAIR ABSENT- depends on androgen action at receptors

Question 18

List the genital structures that are present/ absent in AIS and why

Answer 18

Absent male internal genitalia (No testosterone receptor)
Absent male external genitalia (No DHT receptor)
Absent female internal genitalia (Normal AMH)
Presence of female external genitalia (No DHT receptor)

Question 19

List similarities and differences between Mullerian agenesis and AIS

Answer 19

similarities: both have no uterus, no internal male genitalia, normal breast development in puberty, development of lower 1/3 of vagina

differences

• Mullerian agenesis does have pubic hair
• AIS= 46, XY; Mullerian agenesis= 46, XX
• Mullerian agenesis- testosterone level is normal for females; AIS- testosterone level in adult male range

Question 20

Congenital adrenal hyperplasia is due do a deficiency of _____ which is responsible for:

Answer 20

21-hydroxylase

conversion of cholesterol to cortisol

Question 21

In severe impairment of 21-hydroxylase, levels of CRH/ ACTH are (high/ low)

Answer 21

high, due to lack of cortisol negative feedback

Question 22

How to newborn girls with CAH present?

Answer 22

ambiguous genitalia, present Mullerian structures and ovaries

Question 23

What is the treatment for classic CAH?

Answer 23

glucocorticoids, suppress HPA axis from making excess androgens