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Phenylketonuria: more than a diet disorder, it’s a brain disorder1,2

About phenylketonuria (PKU)

Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine (Phe) metabolism, which can have significant neurodevelopment sequelae.1-3

  • PKU is characterized by a deficiency of phenylalanine hydroxylase (PAH) enzymatic activity resulting in an inability to metabolize the amino acid, Phe1
  • If not adequately controlled, elevated levels of Phe become neurotoxic and disrupt normal neurophysiology2,3
High blood Phe affects the way people with PKU think, feel, and act image

PKU is diagnosed through newborn screening

In the United States and Europe, PKU is readily detected by PKU newborn screening, a blood test which was first instituted in the 1960s.1,6

PKU may be under-diagnosed as some countries have no screening or have only recently adopted newborn screening.8,9

Prevalence of PKU graphic

Learn more about PKU


PKU is an autosomal recessive inborn error of phenylalanine (Phe) metabolism1

Adult challenges in PKU icon

Adult PKU can have many challenges1,3

Stay connected with the latest PKU information

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  1. Ashe K, Kelso W, Farrand S, et al. Psychiatric and cognitive aspects of phenylketonuria: the limitations of diet and promise of new treatments. Front Psychiatry. 2019;10:561. doi:10.3389/fpsyt.2019.00561.
  2. Gentile JK, Ten Hoedt AE, Bosch AM. Psychosocial aspects of PKU: hidden disabilities—a review. Mol Genet Metab. 2010;99(suppl 1):S64-S67.
  3. Brown CS, Lichter-Konecki U. Phenylketonuria (PKU): a problem solved? Mol Genet Metab Rep. 2016;6:8-12.
  4. Bilder DA, Noel JK, Baker ER, et al. Systematic review and meta-analysis of neuropsychiatric symptoms and executive functioning in adults with phenylketonuria. Dev Neuropsychol. 2016;41(4):245-260.
  5. van Wegberg AMJ, MacDonald A, Ahring K, et al. The complete European guidelines of phenylketonuria: diagnosis and treatment. Orphanet J Rare Dis. 2017;12(1):162. doi:10.1186/s13023-017-0685-2.
  6. Vockley J, Andersson HC, Antshel KM, et al; American College of Medical Genetics and Genomics Therapeutic Committee. Phenylalanine hydroxylase deficiency: diagnosis and management guidelines. Genet Med. 2014;16(2):188-200.
  7. Blau N, van Spronsen FJ, Levy HL. Phenylketonuria. Lancet. 2010;376(9750):1417-1427.
  8. Pourfarzam M. Fouzieh Z. Newborn screening for inherited metabolic disorders: news and views. J Res Med Sci. 2013;18(9):801-808.
  9. Rocha JC, MacDonald A. Treatment options and dietary supplements for patients with phenylketonuria. Expert Opin Orphan Drugs. 2018;6(11):667-681.
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