What major health issue can PKU lead to if not detected in infancy?

Phenylketonuria (PKU) is an inherited metabolic disorder that results in the inability to properly metabolize phenylalanine, an amino acid. If PKU is not detected and managed in infancy, the excessive accumulation of phenylalanine can lead to severe neurological deficits. The brain is particularly sensitive to high levels of phenylalanine, which can interfere with normal brain development and function.

Early detection through newborn screening followed by appropriate dietary restrictions can prevent the harmful effects of this condition. By maintaining phenylalanine levels within a safe range through diet, individuals with PKU can lead healthy lives without experiencing the cognitive impairments and developmental delays that would otherwise occur if the disorder went undiagnosed and untreated. Therefore, the major health issue associated with untreated PKU is indeed neurological deficits.