Molecular Biology/Genetics USMLE Step 1 Practice Question
A 32-year-old man with autosomal recessive inheritance disorder (prevalence 1/40,000) presents with progressive neurologic decline. Physical examination reveals BP 118/76, HR 88, RR 16, temperature 37.2°C, SpO2 98%. Serum lysosomal enzyme activity is reduced at 15% of normal. Brain MRI shows no acute abnormalities. He denies family history of similar disease. His unaffected partner has unknown carrier status from the general population. What is the probability their first daughter will be affected?
Answer choices
- A1/100
- B1/4
- C1/40,000
- D1/2Correct answer
- E1/200
- F1/80
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