Abnormal Newborn Screening Results and Additional Testing

If your baby’s newborn screening results are abnormal, your baby will need to have another test.  Not every abnormal result means your baby has a disorder.  It is important to have quick follow-up testing.  Without treatment, PKU can result in harmful effects soon after birth. 
The Utah Newborn Screening Program will contact you and your child’s pediatrician for blood and urine testing.
The Metabolic Clinic at Primary Children’s Hospital cares for babies diagnosed with PKU.
Metabolic Clinic (801) 585-2457

About PKU

Newborn screening began in the 1960’s with the development of the PKU test.  Often, newborn screening is still referred to as the “PKU Test”, but PKU is just one of the many disorders tested for at birth.

People affected by PKU are not able to break down an amino acid called phenylalanine. If untreated, PKU results in a buildup of phenylalanine in the body.  This can cause developmental delays, seizures, brain damage, and even death. Early detection and proper treatment can reduce the severity of symptoms.


PKU is estimated to affect between 1 in every 10,000 to 23,000 babies born in the United States.

Condition Type

PKU is an Amino Acid Disorder.

Also Known As

  • Phenylketonuria
  • Classic Phenylketonuria
  • Phenylalanine Hydroxylase Deficiency
  • Hyperphenylalaninemia - Classic Type
  • PAH Deficiency
  • Phenylalanine