In Phenylketonuria the main aim of first-line therapy is: (A) Replacement of the defective enzymes, (B) Replacement of the deficient product, (C) Limiting the substrate for deficient enzyme, (D) Giving the missing amino acid by diet
Answer is C. In PKU Phenylalanine hydroxylase enzyme is deficient.So alternative pathways are opened. Leading to the formation of Phenylketone,Phenyllactate and Phenylacetate. This can be prevented by limiting the substrate for deficient enzyme.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 236