Question 1

Mutations in particular genes can cause or increase the risk of specific congenital anomalies of the urogenital system.Which gene when mutated is most likely to be responsible for congenital bilateral aplasia of the vas deferens?

A) CFTR
B) AMH RECEPTOR
C) WT1
D) 5α-REDUCTASE
E) PDK1

Accepted Answer

5α-Reductase is an enzyme responsible for the conversion of testosterone to dihydrotestosterone (DHT), which is crucial for the development of male external genitalia in utero. Mutations in the gene encoding 5α-reductase can lead to male pseudohermaphroditism, where individuals have male gonads but their external genitalia are female or ambiguous.

Question 2

What effect would a loss of Shh expression within the urethral plate have on genital development?&#10;A) Development of enlarged genital tubercle&#10;B) Hypospadia&#10;C) An increase in Hoxa13 and Hoxd3 expression in the genital tubercle&#10;D) An increase in Fgf8 expression in the urethral plate

Accepted Answer

Loss of Shh expression in the urethral plate leads to hypospadia, which is a condition where the urethra does not develop properly and opens on the underside of the penis or in the scrotum instead of at the tip of the penis. This is because Shh signaling is necessary for proper development and patterning of the urethral plate.

Question 3

Mutations in particular genes can cause or increase the risk of specific congenital anomalies of the urogenital system.Which gene when mutated is most likely to be responsible for congenital bilateral aplasia of the vas deferens?

A) CFTR
B) AMH RECEPTOR
C) WT1
D) 5α-REDUCTASE
E) PDK1

Accepted Answer

Persistent Müllerian syndrome is caused by mutations in the AMH receptor gene, which encodes the anti-Müllerian hormone receptor. This receptor plays a critical role in male sexual differentiation by inducing regression of the Müllerian ducts, which are the precursors to the female reproductive tract. Mutations in other genes mentioned in the options may cause or increase the risk of other urogenital congenital anomalies, but not specifically persistent Müllerian syndrome.

Question 4

Mutations in particular genes can cause or increase the risk of specific congenital anomalies of the urogenital system.Which gene when mutated is most likely to be responsible for congenital bilateral aplasia of the vas deferens?

A) CFTR
B) AMH RECEPTOR
C) WT1
D) 5α-REDUCTASE
E) PDK1

Accepted Answer

Mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene are known to cause congenital bilateral aplasia of the vas deferens, which is a characteristic feature of cystic fibrosis.

Question 5

What gene is thought to be a direct downstream target of SRY expression?&#10;A) SOX9&#10;B) WF1&#10;C) AMH&#10;D) DESERT HEDGEHOG&#10;E) WNT4

Accepted Answer

SOX9 is a direct downstream target of SRY expression and is required for testis development.

Deck 17: Development of the Reproductive System