NBS Phenylketonuria (Phenylalanine)

The NBS Phenylketonuria (Phenylalanine) test is a newborn screening test used to detect Phenylketonuria (PKU), a rare inherited metabolic disorder in which the body is unable to properly break down an amino acid called phenylalanine. When phenylalanine accumulates in the blood, it can become toxic and may affect brain development and nervous system function. Early identification through newborn screening allows timely dietary management, helping prevent serious complications and ensuring healthy growth and development.

Who Should Get This Test Done?

This test is recommended for:

●     All newborn babies as part of routine newborn screening programs

●     Infants with a family history of Phenylketonuria (PKU)

●     Newborns born to parents known to be carriers of PKU-related genetic mutations

●     Babies showing signs of metabolic disorders, although symptoms may not be present in the newborn period

●     Infants requiring follow-up testing after an abnormal newborn screening result

Why Consider This Test?

Phenylketonuria can cause irreversible intellectual disability, developmental delays, behavioural problems, and neurological complications if left untreated. Since symptoms often do not appear immediately after birth, newborn screening plays a critical role in early detection. Identifying elevated phenylalanine levels soon after birth enables prompt dietary intervention, which can significantly reduce the risk of long-term complications and support normal physical and cognitive development.

More Information About the Test

This test is typically performed using a few drops of blood collected from the baby’s heel, usually within the first few days after birth. The sample is analysed to measure phenylalanine levels in the blood. Elevated levels may indicate PKU or another disorder affecting phenylalanine metabolism and may require confirmatory testing. The test is a part of newborn screening (NBS) programs designed to detect serious but treatable conditions before symptoms develop.

Other Names

●     Newborn Screening for Phenylketonuria

●     PKU Screening Test

●     Phenylalanine Screening Test

●     Newborn Phenylalanine Test

●     Phenylketonuria (PKU) Newborn Screen

●     NBS PKU Test