Final answer:
The development of infants with Phenylketonuria (PKU) largely depends on early diet modifications low in phenylalanine, as unrecognized and untreated high phenylalanine levels can lead to significant brain and central nervous system damage.
Step-by-step explanation:
The effect that Phenylketonuria (PKU) has on an infant's development will depend primarily on the adherence to a corrective diet instituted early.
PKU is an inherited metabolic disorder where the enzyme phenylalanine hydroxylase is deficient, leading to the accumulation of phenylalanine to toxic levels in the body, notably affecting the central nervous system and brain. Symptoms of untreated PKU include delayed neurological development, intellectual disability, and seizures, among other complications.
Pregnant individuals with PKU must manage their phenylalanine levels to prevent fetal exposure, which can lead to developmental issues such as heart defects and microcephaly. Early diagnosis and a strict diet low in phenylalanine are vital to prevent damage and lessen symptoms.