Pediatrics Hyperphenylalaninemia is due to defect in the enzyme: A Phenylalanine hydroxylase: B Tyrosinase C Homogentisic acid oxidase D Ornithine transcarbamylase 💡 Explanation Hyperphenylalaninemia is due to defect in the enzyme: ✓ Correct Answer: A. Phenylalanine hydroxylase: