The median maximal fall in Hb was -2.0 g/dL (range -5.6 to 0) in the 25 confirmed hemizygous males, -2.0 g/dL (range -4.1 to -1.1) in the 5 confirmed heterozygous females, and -1.7 g/dL (range -3.7 to 0) in the 16 patients without confirmed G6PD deficiency. Here, GSTM1 is linked to G6PD deficiency.