Phenylketonuria (PKU) if untreated manifests with intellectual disability. The dietary management requires restriction of phenylalanine but supplementation of:
- A Tryptophan
- B Methionine
- C Tyrosine ✓
- D Leucine
Correct answer: C. Tyrosine
Explanation
In PKU, phenylalanine hydroxylase (PAH) is deficient, blocking phenylalanine conversion to tyrosine. Tyrosine therefore becomes an essential amino acid that must be supplied in the diet. The PKU diet restricts phenylalanine intake to prevent neurotoxic phenylalanine/phenylpyruvate accumulation while supplementing tyrosine to maintain normal protein synthesis, catecholamine production, and thyroid hormone synthesis.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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