ICD-11 classes
20 Developmental anomalies
LD90 — Conditions with disorders of intellectual development as a...
5C55.01 — Lesch-Nyhan syndrome
ICD-11 5C55.01 — Lesch-Nyhan syndrome
Lesch-Nyhan syndrome (LNS) is the most severe form of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency, a hereditary disorder of purine metabolism, and is associated with uric acid overproduction (UAO), neurological troubles, and behavioural problems. Patients are normal at birth. Psychomotor delay becomes evident within 3 to 6 months with a delay in head support and sitting, hypotonia and athetoid movements. Sandy urine in diapers or crystalluria with urinary tract obstruction are common forms of presentation. Patients usually show mild to moderate intellectual deficit. Diagnosis is suspected when psychomotor delay occurs in a patient with elevated UA in blood and urine. Undetectable HPRT enzyme activity in peripheral blood or in intact cells (erythrocyte, fibroblast) and molecular genetic testing confirm the diagnosis. Inheritance is X-linked recessive.
The diagnosis includes nothing.
The diagnosis excludes nothing.
It has no clarifying diagnoses.
The diagnosis is coded elsewhere: