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Summary

Phenylketonuria (PKU) is a type of amino acid metabolism disorder. It is inherited. If you have it, your body can't process phenylalanine (Phe). Phe is an amino acid, a building block of proteins. It is in almost all foods. If your Phe level gets too high, it can damage your brain and cause severe intellectual disability. All babies born in U.S. hospitals must now have a screening test for PKU. This makes it easier to diagnose and treat the problem early.

The best treatment for PKU is a diet of low-protein foods. There are special formulas for newborns. For older children and adults, the diet includes many fruits and vegetables. It also includes some low-protein breads, pastas, and cereals. Nutritional formulas provide the vitamins and minerals you can't get from their food.

Babies who get on this special diet soon after they are born develop normally. Many have no symptoms of PKU. It is important to stay on the diet for the rest of your life.

NIH: National Institute of Child Health and Human Development

Start Here

• About Phenylketonuria (PKU) (Eunice Kennedy Shriver National Institute of Child Health and Human Development) Also in Spanish
• Phenylketonuria (Mayo Foundation for Medical Education and Research) Also in Spanish
• PKU (Phenylketonuria) in Your Baby (March of Dimes Foundation) Also in Spanish

Symptoms

• What Are Common Symptoms of Phenylketonuria (PKU)? (Eunice Kennedy Shriver National Institute of Child Health and Human Development) Also in Spanish

Diagnosis and Tests

• How Do Health Care Providers Diagnose Phenylketonuria (PKU)? (Eunice Kennedy Shriver National Institute of Child Health and Human Development) Also in Spanish
• Phenylketonuria (PKU) Screening (National Library of Medicine) Also in Spanish

Treatments and Therapies

• What Are Common Treatments for Phenylketonuria (PKU)? (Eunice Kennedy Shriver National Institute of Child Health and Human Development) Also in Spanish

Related Issues

• Sugar Substitutes (American Academy of Family Physicians) Also in Spanish

Genetics

• Learning about Phenylketonuria (PKU) (National Human Genome Research Institute)
• Phenylketonuria: MedlinePlus Genetics (National Library of Medicine)
• Tetrahydrobiopterin deficiency: MedlinePlus Genetics (National Library of Medicine)

Clinical Trials

• ClinicalTrials.gov: Phenylketonurias (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Experimental Animal Models of Phenylketonuria: Pros and Cons.
• Article: A Cross-Sectional Study on Protein Substitutes for Paediatric Phenylketonuria Diet: Time...
• Article: Factors associated with psycho-behavioral problems among 100 children with phenylketonuria aged...
• Phenylketonuria -- see more articles

Find an Expert

• Eunice Kennedy Shriver National Institute of Child Health and Human Development Also in Spanish
• March of Dimes Foundation Also in Spanish

Patient Handouts

• Phenylketonuria (Medical Encyclopedia) Also in Spanish
• Serum phenylalanine screening (Medical Encyclopedia) Also in Spanish