The genetic condition called phenylketonuria results from a defect in a gene called PAH which helps create phenylalanine hydroxylase, the enzyme that breaks down the amino acid phenylalanine. What is the outcome of this condition and the lack of this enzyme?
A) Phenylalanine accumulates.
B) Phenylalanine is completely used up, deleting its stores in the body.
C) A different enzyme begins breaking down phenylalanine.
D) Phenylalanine hydroxylase accumulates.

Question

Quizplus · Accepted Answer

Phenylketonuria (PKU) leads to the accumulation of phenylalanine in the body because the enzyme phenylalanine hydroxylase, which is necessary to break down phenylalanine, is deficient or defective.

The Genetic Condition Called Phenylketonuria Results from a Defect in a Gene