Phenylketonuria (PKU) is a rare genetic condition in which the body cannot effectively metabolize an amino acid called phenylalanine (Phe) due to the missing or defective activity of an enzyme called phenylalanine hydroxylase (PAH). High levels of Phe, which is found in all foods containing protein, can lead to neurological and behavioral impairment. The primary treatment is a low-Phe diet.

Symptoms of PKU vary from mild to severe. The most severe form of the disease is known as classic PKU. PKU is typically diagnosed at birth through a blood test. Without treatment, a high level of blood Phe can develop which is toxic to the brain. Permanent cognitive disability, seizures, behavioral problems and psychiatric disorders can result.

The reported incidence of PKU from newborn screening programs ranges from one in 13,500 to 19,000 newborns in the United States. The incidence varies in other parts of the world. The disorder is inherited in an autosomal recessive genetic manner, meaning that a child is affected when each parent passes on one copy of the mutated gene.

Learn about our development efforts for PKU .

Resources: NIH Genetics Home Reference , National Organization for Rare Disorders

The following organizations may be a resource for information and support for people with PKU and those around them:

Children's PKU Network

Children's PKU Network (CPN) was founded in 1991 to address the special needs and concerns of individuals and families with the metabolic disorder Phenylketonuria (PKU). CPN is a non-profit organization dedicated to maintaining an agenda of public awareness, education, and direct assistance through a variety of programs that enable individuals diagnosed with PKU and other metabolic disorders reach their full potential.

National PKU Alliance

The NPKUA provides information and support to adults and families, advocates for the reimbursement of medical foods, and invests in targeted and peer reviewed research for the development of new therapies and a future cure for PKU. It was formed in 2008 by parents, grandparents and individuals across the country. NPKUA is the first national non-profit organization to unite adults, families, regional and statewide PKU organizations, the medical community, and PKU-friendly businesses to make a difference in the lives of people with PKU.

National PKU News

Starting in 1989, National PKU News published a newsletter three times per year that provided essential news and information to the PKU community. With more than 2400 subscribers at its peak, the newsletter was a vital communication tool for the PKU community before the listserv, Facebook and other resources. With subscribers in 35 countries, who included parents, young adults with PKU, professionals, grandparents, relatives and other persons connected to families of affected persons, it was a truly global resource. Much communication about and support for the PKU community goes on online. For this reason, the newsletter was discontinued in early 2015. With a focus on developing How Much Phe and our Amino Acid Analysis Program, National PKU News continues to provide a vital resource to the PKU community. The organization also administers the Guthrie-Koch Scholarship program, for college-age people with PKU.

Global Genes

Global Genes is a non-profit patient advocacy organization working to eliminate the challenges of rare disease by building awareness, educating the global community, and providing critical connections and resources that equip advocates to become activists for their disease.  Global Genes promotes the needs of the rare disease community under a unifying symbol of hope – the Blue Denim Genes Ribbon™. Numerous tools, resources and educational events can be found on the Global Genes website

National Organization for Rare Disorders

The National Organization for Rare Disorders (NORD) is a unique federation of voluntary health organizations dedicated to helping people with rare "orphan" diseases and assisting the organizations that serve them. NORD is committed to the identification, treatment and cure of rare disorders through programs of education, advocacy, research and service. In the US, NORD is also the official sponsor of Rare Disease Day, an annual global observance that raises awareness of rare diseases and elevates them into the public consciousness as an important health issue that cannot be ignored.


EURORDIS is a non-governmental patient-driven alliance of more than 700 rare disease patient organisations in more than 60 countries. EURORDIS strives to build a strong pan-European community of patient organisations and people living with a rare disease, to be their voice at the European level, and - directly or indirectly - to fight against the impact of rare diseases on their lives. EURORDIS leads global efforts for Rare Disease Day and the online social platform for people living with or affected by a rare diseases RareConnect. EURORDIS represents the voice of an estimated 30 million people living with a rare disease in Europe. Follow @eurordis or see the EURORDIS Facebook page. For more information visit: