A 46, XY newborn presents with ambiguous external genitalia and cryptorchidism. At age 13, he develops progressive virilization with increased muscle mass, deepening voice, and facial hair. Vital signs: BP 118/76, HR 88, RR 16, temp 37.2°C, SpO2 98%. Laboratory studies show testosterone 650 ng/dL (normal for Tanner stage IV). Pelvic ultrasound reveals normal internal reproductive structures. He denies exogenous androgen exposure. Which of the following enzyme defects most likely explains his presentation?
- A)Mutation causing absent GnRH secretion
- B)Deficient conversion of testosterone to dihydrotestosteroneGABARITO
- C)Failure of Müllerian inhibiting factor production
- D)Loss of gonadal Sertoli cells in utero
- E)Inability to respond to estrogen
Explicação
5 alpha reductase deficiency impairs conversion of testosterone to dihydrotestosterone, the androgen required for normal male external genital development. Internal male structures are present because testosterone is still produced, and virilization often incr... Ver explicação completa e trilha adaptativa →