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Tetrahydrobiopterin-responsive hyperphenylalaninemia/phenylketonuria

Disease definition

A form of phenylketonuria (PKU), an inborn error of amino acid metabolism, characterized by mild to moderate symptoms of PKU including impaired cognitive function, seizures, and behavioral and developmental disorders, and a marked reduction of elevated phenylalanine concentrations after oral loading with tetrahydrobiopterin (BH4), an essential cofactor of phenylalanine hydroxylase.


Classification level: Subtype of disorder
  • Synonym(s):
    • BH4-responsive HPA/PKU
    • BH4-responsive hyperphenylalaninemia/phenylketonuria
    • Tetrahydrobiopterin-responsive HPA/PKU
  • Prevalence: Unknown
  • Inheritance: Autosomal recessive 
  • Age of onset: Infancy, Neonatal
  • ICD-10: E70.1
  • OMIM: -
  • UMLS: -
  • MeSH: -
  • GARD: -
  • MedDRA: -

Detailed information

Article for general public


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