Three females with G6PD deficiency (range 0.39–1.26 U/ gHb) included 2 homozygous mutation (1 G6PD Mahidol and 1 G6PD Aures) and 1 coinheritance of a heterozygous G6PD mutation (G6PD Aures and G6PD Quing Yan). The gene discussed is G6PD; the disease is hyperinsulinemic hypoglycemia, familial, 4.