Orphanet: Phenylketonuria

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Disease definition

A rare inborn error of amino acid metabolism characterized by elevated blood phenylalanine and low levels or absence of phenylalanine hydroxylase enzyme. If not detected early or left untreated, the disorder manifests with mild to severe mental disability.


Classification level: Disorder
  • Synonym(s):
    • PAH deficiency
    • PKU
    • Phenylalanine hydroxylase deficiency
  • Prevalence: 1-5 / 10 000
  • Inheritance: Autosomal recessive 
  • Age of onset: Infancy
  • ICD-10: E70.0  E70.1
  • OMIM: 261600
  • UMLS: C0031485
  • MeSH: D010661
  • GARD: 7383
  • MedDRA: 10034872

Detailed information

Article for general public


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