G6PD and autoimmune hemolytic anemia: The severity of drug-induced acute haemolytic anaemia (AHA) in G6PD deficient persons depends on several factors, the most important of which are: (a) drug dosage, (b) the genotypic combinations at the G6PD locus (which are different in males versus females), and (c) the allelic variants of the G6PD gene.