Phenylketonuria (PKU) is caused by deficiency of which enzyme, and what is the typical chronic dietary management?

• A. Deficiency of Hepatic Phenylalanine Hydroxylase With High Phenylalanine and Low Tyrosine; Phenylalanine-Free Diet With Tyrosine Supplementation
• B. Deficiency of Hepatic Tyrosine Hydroxylase With High Tyrosine and Low Phenylalanine; Tyrosine-Rich Diet
• C. Excess Phenylalanine Intake; No Dietary Restriction
• D. Deficiency of Phenylalanine; Treat With Phenylalanine Supplementation

Answer: (A)