Which of the following disorders is characterized by an inability to convert phenylalanine to tyrosine due to a deficiency of the enzyme phenylalanine hydroxylase?

A Albinism
B Phenylketonuria (PKU) ✓
C Homocystinuria
D Maple syrup urine disease

Explanation

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase, which is necessary for the conversion of phenylalanine to tyrosine. If left untreated, PKU can lead to intellectual disability and other serious health problems.

Mnemonic

PKU = Peculiar Kids Understand (the importance of diet)

Source

Nelson Textbook of Pediatrics
Metabolic and Nutritional Disorders Genetic Disorders Amino Acid Metabolism Disorders Hard MEDICAL Confidence: high