Congenital Methemoglobinemia. a Clinical and Biochemical Study of a Case.

Congenital methemoglobinemia is an unusual condition in which a large amount of intracellular hemoglobin exists as methemoglobin-pigment in which the hemoglobin iron is in the ferric state and incapable of carrying oxygen. The congenital type of methemoglobinemia is present from birth and is characterized by the constancy of the level of methemoglobin, by the relatively mild associated symptoms, and by polycythemia with no evidence of excessive blood destruction. There are 15 verified cases of congenital methemoglobinemia in the literature (1-10) and 10 additional cases of idiopathic methemoglobinemia (11-15) in which definite information as to the congenital aspect was lacking. In all of these cases the abnormalpigmentwas identified spectroscopically. The subject of this study was a young man who presented the typical clinical picture of congenital methemoglobinemia. We have now followed him for five years-sufficient time to evaluate different forms of therapy for this condition.