Biochemistry A child with hypopigmented hair and mentally retarded with mousy odour urine. Enzyme deficient is? A Cystathione synthase B Tyrosine hydroxylase C Phenylalanine hydroxylase D Tyrosine transaminase 💡 Explanation A child with hypopigmented hair and mentally retarded with mousy odour urine. Enzyme deficient is? ✓ Correct Answer: C. Phenylalanine hydroxylase