ICD-11 classes
08 Diseases of the nervous system
Multiple sclerosis or other white matter disorders
8A44 — Leukodystrophies
8A44.3 — Certain specified leukodystrophies
5C50.0 — Phenylketonuria

ICD-11 5C50.0 — Phenylketonuria

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.

The diagnosis includes nothing.

The diagnosis excludes nothing.

Diagnosis with code 5C50.0 contains 5 clarifying diagnoses:

1. 5C50.00 — Classical phenylketonuria
2. 5C50.01 — Nonclassical phenylketonuria
3. 5C50.02 — Embryofetopathy due to maternal phenylketonuria
4. 5C50.0Y — Other specified phenylketonuria
5. 5C50.0Z — Phenylketonuria, unspecified

The diagnosis is coded elsewhere:

• Inborn errors of amino acid or other organic acid metabolism #4711
• Phenylketonuria #4712
• Conditions with disorders of intellectual development as a relevant clinical feature #23735
• Phenylketonuria #23747