Embryology USMLE Step 1 Practice Question
A 16-year-old girl presents with primary amenorrhea and is found to have absent uterus and fallopian tubes on pelvic ultrasound, but normal ovarian function with appropriate secondary sexual characteristics. Her kidney ultrasound reveals unilateral renal agenesis. Genetic testing shows a normal 46,XX karyotype. Which of the following embryologic defect best explains this constellation of findings?
Answer choices
- AAbnormal development of the mesonephric (Wolffian) duct
- BPersistence of the mesonephric (Wolffian) duct in a female
- CFailure of the paramesonephric (Müllerian) duct to developCorrect answer
- DIncomplete fusion of the urogenital and anal portions of the cloaca
- EFailure of germ cells to migrate from the yolk sac
- FFailure of the sinovaginal bulbs to fuse with the urogenital sinus
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.