What condition is characterized by a deficiency in the enzyme phenylalanine hydroxylase?

Phenylketonuria (PKU) is characterized by a deficiency in the enzyme phenylalanine hydroxylase. This enzyme is crucial for the metabolism of the amino acid phenylalanine, converting it into tyrosine. When phenylalanine hydroxylase is deficient or nonfunctional, phenylalanine accumulates in the body, leading to toxic levels that can result in severe neurological damage and intellectual disabilities if not managed through dietary restrictions.

Individuals with PKU must adhere to a strict low-phenylalanine diet, often starting from infancy, to prevent the adverse effects of the condition. Early diagnosis and intervention, typically through newborn screening programs, are vital for preventing the serious consequences associated with this enzyme deficiency.

In contrast, other choices refer to different conditions with distinct enzyme deficiencies or genetic mutations that do not involve phenylalanine hydroxylase.