Which of the following metabolic disorders is characterized by an inability to break down the amino acid phenylalanine, leading to intellectual disability and other neurological problems if left untreated?

A Maple syrup urine disease
B Phenylketonuria ✓
C Tyrosinemia
D Homocystinuria

Explanation

Phenylketonuria (PKU) is a genetic disorder characterized by an inability to break down the amino acid phenylalanine, leading to intellectual disability and other neurological problems if left untreated.

Source

Harper's Illustrated Biochemistry
Metabolic and Nutritional Disorders Amino Acid Metabolism Inborn Errors of Metabolism Hard NURSING Confidence: high