Question

Phenylketonuria (PKU) testing is performed on a newborn. The nurse plans to explain to the mother the purpose of this screening test. What does this test determine?

A. If the infant is positive for PKU
B. If the mother is a carrier for PKU
C. The risk for the mother developing PKU later
D. The risk for the infant developing PKU when older

Answer 1

The purpose of PKU testing in newborns is to detect if the infant is positive for Phenylketonuria (PKU), a genetic disorder where the individual lacks the enzyme to properly metabolize phenylalanine, leading to neurological damage if not managed with a low-phenylalanine diet.

Step-by-step explanation:

Phenylketonuria (PKU) testing in newborns is crucial for early detection of PKU, a genetic disorder. This screening test is performed to determine A. If the infant is positive for PKU, which means it checks if the newborn lacks sufficient activity of the enzyme phenylalanine hydroxylase. Without this enzyme activity, the infant cannot break down phenylalanine into tyrosine effectively, leading to potentially toxic levels of phenylalanine and subsequent damage to the brain and central nervous system. Symptoms can include delayed neurological development, hyperactivity, intellectual disability, seizures, and other serious complications. An early diagnosis can lead to the implementation of a modified diet low in phenylalanine, which is essential in reducing the severity of these symptoms and preventing damage.