Molecular Biology/Genetics USMLE Step 1 Practice Question
A 28-year-old white female and her 25-year-old white male partner present for genetic counseling. Both have one sibling with cystic fibrosis confirmed by sweat chloride testing (98 mEq/L). The couple is asymptomatic with normal pulmonary function tests and no personal history of pancreatic insufficiency. They desire preconception risk assessment for cystic fibrosis transmission to offspring. Which method most appropriately determines their carrier status and calculates recurrence risk?
Answer choices
- AKaryotype analysis
- BBiochemical testing
- CWestern blot analysis
- DPolymerase chain reaction (PCR)Correct answer
- EFluorescence in situ hybridization (FISH)
- FSickle cell carrier screening
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