What is a PKU screening test?A PKU screening test is a blood test given to newborns 24–72 hours after birth. PKU stands for phenylketonuria, a rare disorder that prevents the body from properly breaking down a substance called phenylalanine (Phe). Phe is part of proteins that are found in many foods and in an artificial sweetener called aspartame.If you have PKU and eat these foods, Phe will build up in the blood. High levels of Phe can permanently damage the nervous system and brain, causing a variety of health problems. These include seizures, psychiatric problems, and severe intellectual disability.PKU is caused by a genetic mutation, a change in the normal function of a gene. Genes are the basic units of heredity passed down from your mother and father. For a child to get the disorder, both the mother and father must pass down a mutated PKU gene.Although PKU is rare, all newborns in the United States are required to get a PKU test.The test is easy, with virtually no health risk. But it can save a baby from lifelong brain damage and/or other serious health problems.If PKU is found early, following a special, low-protein/low-Phe diet can prevent complications.There are specially-made formulas for infants with PKU.People with PKU need to stay on the protein/low-Phe diet for the rest of their lives.Other names: PKU newborn screening, PKU test
