label: hereditary methemoglobinemia
label_lc: hereditary methemoglobinemia
description: Methemoglobinemia inherited in an autosomal recessive pattern. It is caused by deficiency of the enzyme NADH methemoglobin reductase or the presence of abnormal hemoglobin M. It presents with cyanosis early in life. There is no evidence of cardiopulmonary disease present.