5C50.0

ICD-11 MMS 2026-01

Phenylketonuria

Description

Phenylketonuria is a hereditary metabolic disease, characterised by deficiency of phenylalanine hydroxylase, an enzyme necessary for the transformation of phenylalanine into tyrosine. Untreated, phenylketonuria leads to mental retardation, sometimes profound, as well as hypopigmentation. Dietary phenylalanine restriction allows patients to lead almost normal lives.

Exclusions from above levels

  • http://id.who.int/icd/entity/1191191920 – Disorders of lipoprotein metabolism or certain specified lipidaemias
  • 3A10.Z – Hereditary haemolytic anaemia due to enzyme deficiency
  • 5A71.01 – Congenital adrenal hyperplasia
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  • 5A81.1 – 5-alpha-reductase deficiency
  • LD28.01 – Marfan syndrome
  • LD28.1 – Ehlers-Danlos syndrome
  • LD2A.4 – androgen resistance syndrome
  • 18 – Pregnancy, childbirth or the puerperium
  • http://id.who.int/icd/entity/1004987305 – Transitory endocrine or metabolic disorders specific to fetus or newborn

Child codes

  • 5C50.00 – Classical phenylketonuria
  • 5C50.01 – Nonclassical phenylketonuria
  • 5C50.02 – Embryofetopathy due to maternal phenylketonuria
  • 5C50.0Y – Other specified phenylketonuria
  • 5C50.0Z – Phenylketonuria, unspecified

Sibling codes

  • 5C50.1 – Disorders of tyrosine metabolism
  • 5C50.2 – Disorders of histidine metabolism
  • 5C50.3 – Disorders of tryptophan metabolism
  • 5C50.4 – Disorders of lysine or hydroxylysine metabolism
  • 5C50.5 – Disorders of the gamma-glutamyl cycle
  • 5C50.6 – Disorders of serine metabolism
  • 5C50.7 – Disorders of glycine metabolism
  • 5C50.8 – Disorders of proline or hydroxyproline metabolism
  • 5C50.9 – Disorders of ornithine metabolism
  • 5C50.A – Disorders of urea cycle metabolism
  • 5C50.B – Disorders of methionine cycle or sulphur amino acid metabolism
  • 5C50.C – Disorders of beta or omega amino acid metabolism
  • 5C50.D – Disorders of branched-chain amino acid metabolism
  • 5C50.E – Organic aciduria
  • 5C50.F – Disorders of peptide metabolism
  • 5C50.G – Trimethylaminuria
  • 5C50.Y – Other specified inborn errors of amino acid or other organic acid metabolism
  • 5C50.Z – Inborn errors of amino acid or other organic acid metabolism, unspecified

Foundation entity

Phenylketonuria – http://id.who.int/icd/entity/444122923

Part of: 5C50: Inborn errors of amino acid or other organic acid metabolism › 05: Endocrine, nutritional or metabolic diseases