Phenylketonuria is caused by
A) an inherited lack of an enzyme that produces tyrosine.
B) accumulation of waste products in the brain.
C) neurofibrillary tangles.
D) toxic chemicals released by a virus.
E) leakage from glutamate into the brain blood system.

Question

Quizplus · Accepted Answer

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary to metabolize phenylalanine into tyrosine. This leads to a buildup of phenylalanine and its byproducts in the body, causing neurological problems if left untreated.

Phenylketonuria Is Caused by