Metabolism USMLE Step 1 Practice Question
A 3 year old girl is brought in for sensitivity to sunlight and poor visual acuity. Examination shows very light skin and hair compared with her parents, nystagmus, and decreased retinal pigment. Hearing is normal and she has no bleeding diathesis or recurrent infections. Which of the following enzyme deficiencies is the most likely cause?
Answer choices
- AGalactokinase
- BTyrosinaseCorrect answer
- CPhenylalanine hydroxylase
- DHexosaminidase A
- ECystathionine beta synthase
- FLYST gene (Chediak-Higashi syndrome)
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