Which of the following metabolic disorders is characterized by an inability to break down the amino acid phenylalanine, leading to its accumulation in the body?

A Albinism
B Phenylketonuria ✓
C Homocystinuria
D Tyrosinemia

Explanation

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase, leading to an accumulation of phenylalanine in the body.

Mnemonic

Phe = phenyl, K = key to unlock the disorder

Source

Guyton and Hall Textbook of Medical Physiology
Metabolic and Nutritional Disorders Genetic Disorders Amino Acid Metabolism Disorders Medium MEDICAL Confidence: high