What is phenylketonuria?

Phenylketonuria (PKU) is indeed a metabolic disorder that specifically affects the metabolism of amino acids, particularly phenylalanine. In individuals with PKU, there is a deficiency or absence of an enzyme known as phenylalanine hydroxylase, which is crucial for converting phenylalanine into tyrosine. When this conversion does not occur properly, phenylalanine accumulates in the body, leading to a variety of neurological and developmental issues if left untreated. This condition is typically diagnosed through newborn screening, and management often includes a strict dietary regimen that limits phenylalanine intake to prevent harmful effects.

The other options relate to different metabolic conditions or disorders that do not describe PKU. For example, the first option pertains to galactose metabolism, which relates to galactosemia, while the third option addresses disorders involving the adrenal glands, such as adrenal insufficiency, and the fourth option refers to congenital hypothyroidism, which involves impaired thyroid function. Understanding PKU as a specific disorder of amino acid metabolism helps differentiate it from these other conditions.