Molecular Biology/Genetics USMLE Step 1 Practice Question
A 32-year-old pregnant woman at 28 weeks gestation is concerned about her female fetus inheriting glucose-6-phosphate dehydrogenase (G6PD) deficiency. Her 6-year-old son has the disease with documented enzyme activity of 2 U/g Hb (normal: 6-15 U/g Hb). The father is clinically normal with normal G6PD levels. The mother is asymptomatic with intermediate enzyme activity. Prenatal ultrasound shows normal fetal development. Which statement most accurately describes the inheritance pattern and likely status of her female fetus?
Answer choices
- AThe baby has a 50% chance of being a carrierCorrect answer
- BThe baby has a 25% chance of clinical disease
- CThe baby will be a carrier
- DThe baby has a 50% chance of clinical disease
- EThe baby will have clinical disease
- FThe baby has a 50% chance of being completely unaffected with normal enzyme activity
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