Several quantitative and qualitative assays are available for the diagnosis of G6PD deficiency through measurement of residual G6PD activity in whole blood.9, 10 Qualitative tests cannot, however, stratify women with intermediate activity above 30‐40% normal G6PD activity, and quantitative tests do not provide information regarding relative ratios of allele representation in a heterozygous female red blood cell population. This evidence concerns the gene G6PD and G6PD deficiency.