contributes to genotype Mutation Hemoglobin Genotype M CYB5R3 Mutation DIA 1 Mutation Methemoglobinemia Mutation Request inclusion into relevant ontology None NADH-Cytochrome b5 Reductase 3 Mutation A mutation in the NADH-Cytochrome b5 Reductase 3 gene, CYB5R3, that contributes to the presence of methemoglobinemia (type I or II). Diaphorase Mutation