ICD-11 classes
03 Diseases of the blood or blood-forming organs
Anaemias or other erythrocyte disorders
3A92 — Hereditary methaemoglobinaemia

ICD-11 3A92 — Hereditary methaemoglobinaemia

Hereditary methemoglobinemia (HM) is a rare red cell disorder classified principally into two clinical phenotypes: autosomal recessive congenital (or hereditary) methemoglobinemia types I and II (RCM/RHM type 1; RCM/RHM type 2). In RCM type 1, well-tolerated cyanosis from birth is the only symptom. RCM type 2, with global loss of Cb5R function, is much more severe; the cyanosis is accompanied by neurological dysfunction (with intellectual deficit, microcephaly, growth retardation, opisthotonus, strabismus and hypertonia), which usually becomes evident during the first four months of life.

The diagnosis includes nothing.

The diagnosis excludes nothing.

It has no clarifying diagnoses.