Final answer:
Newborns are tested for PKU a day after birth to identify the need for a modified diet that is essential in preventing severe symptoms associated with the disorder. Early detection and dietary management can significantly improve outcomes in affected infants.
Step-by-step explanation:
Newborns are tested for Phenylketonuria (PKU) a day after birth. PKU is a genetic disorder that affects about 1 in every 15,000 births in the United States. It is characterized by the inability to break down the amino acid phenylalanine due to insufficient activity of the enzyme phenylalanine hydroxylase. When phenylalanine accumulates, it can lead to toxic levels in the body and cause damage to the central nervous system and brain. Symptoms of PKU can include delayed neurological development, hyperactivity, intellectual disability, seizures, and skin rash. It is critical for pregnant people with PKU to manage their diet as excess phenylalanine can cross the placenta and affect fetal development, potentially resulting in heart defects, and physical or intellectual disabilities.
Newborn screening for PKU is essential because the earlier a modified diet is started, the less severe the symptoms will be. The diet should be low in phenylalanine to prevent further symptoms and damage, with careful monitoring of phenylalanine intake from artificial sweeteners like aspartame, certain animal products, and starches.