Question:medium

Phenylketonuria is caused by:

Show Hint

Phenylketonuria is an autosomal recessive disorder detected through newborn screening. Early dietary management can prevent its adverse effects.
Updated On: Jan 13, 2026
  • Tyrosine hydroxylase
  • Phenylalanine hydroxylase (PAH)
  • Methionine synthase
  • Argininosuccinate lyase
Show Solution

The Correct Option is B

Solution and Explanation

Phenylketonuria (PKU), a genetic condition, arises from insufficient phenylalanine hydroxylase (PAH) enzyme activity.

The PAH enzyme metabolizes the amino acid phenylalanine into tyrosine. Insufficient PAH function results in elevated, toxic phenylalanine levels in the body, causing significant intellectual impairment, developmental delays, and other neurological issues if left unmanaged. Dietary restriction of phenylalanine is the standard treatment for PKU.

Was this answer helpful?
0