Phenylketonuria PKU

Phenylketonuria (PKU) is a genetically determined metabolic disorder that is highly treatable with diet and supplements. It is an inherited disease in which the body cannot metabolize an amino acid called phenylalanine. Normally phenylalanine is metabolized and converted into tyrosine, another amino acid, but if it stays as phenylalanine, there will be too much of it, and high levels of phenylalanine are harmful to the brain. Following the prescribed diet for PKU is a lifelong endeavor that requires a lot of support from family and your health care provider. If your child is able to strictly follow the diet and supplement regimen, he should be able to live a full, active life.

  • About one in 15,000 babies is born with PKU in the United States.
  • PKU leads to a build-up of the amino acid phenylalanine, which is toxic to the nervous system.
  • Without treatment, PKU can cause intellectual disabilities.
  • PKU does not shorten life expectancy, with or without treatment.
  • Newborn screening for PKU is required in all 50 states.
  • PKU is usually identified by newborn screening.
  • A child’s outlook is very good if she strictly follows the diet.
  • If treatment begins no later than 2 to 3 weeks of a baby’s life, and the diet is strictly followed, the child with PKU can be normal.
  • There are no gender differences in risk factors or severity of PKU.

How Boston Children’s Hospital approaches PKU

The Metabolism Program at Boston Children’s Hospital, part of the Division of Genetics, takes a comprehensive, multidisciplinary approach to testing for and treating children with PKU. Our dedicated team of physicians, nutritionists, nurses, laboratory technicians, social workers and psychologists are committed to helping children with this highly treatable condition. PKU requires life-long care, and our multidisciplinary team will work with you and your child to help him grow into a healthy adult.

Phenylketonuria: Reviewed by Harvey Levy, MD
© Boston Children’s Hospital, 2012