Hereditary methemoglobinemia in Alaskan Eskimos and Indians.

acterized by cyanosis, a variable amount of hemoglobin in the oxidized form methemoglobin, a compensatory polycythemia, and no other pathologic changes. According to a recent review by Gibson1 fewer than 50 cases have been reported, although Dines2 suggests that there are more than 100. Available evidence indicates that the condition is inherited as a recessive trait.3 In air, hemoglobin umidergoes a slow spontaneous oxidation to metilemoglobin and, as shown by Warburg,4 is kept in the reduced state in the red cell by an enzymatic System which utilizes glucose as substrate. The oxidation of glucose generates reduced pyridine nucleotides which in turn reduce methemoglobin by an electron transfer mechanism tilat is Ilot fully understood. Huennekens et al.2’ have attempted to isolate a inethernoglohin reductase from red cells. Barcroft et al.3 and Sievers and RyOI16 showed that the rate of reduction of methemoglobin in cells of persons with hereditary methemoglobinernia is lower than in normal cells. Gibson,7 largely because of the marked effectiveness of methylene blue in reducing methemoglobin in methemoglohinernic cells, suggested that the enzyme diaphorase was missing in methemoglobinemic cells. Eder, Finch and McKee,8 however, showed that flavin adenine dinucleotide, a co-enzyme of the known diapilorases, was I)resent in normal amounts in methemoglobinemic cells. The present report describes an epidemiologic study of hereditary methemnoglobinernia in Alaskan Eskimos and Indians, where its prevaleiice is comparatively high. Evidence will be preselltel to show that the level of methenloglobin in this condition varies with some environmental factor which may be dietary intake of ascorbic acid.