Our approach to a genetic analysis of G6PD deficiency in the Saudi population was to identify haplotypes of G6PD using a combination of DNA sequencing of exons 3, 4, 5, 6, 7, 9, 10, 11 and 12 and introns 11 and 13, utilising physical linkage to define G6PD haplotypes in male patients, and PHASE analysis to reconstruct haplotypes in female patients. This evidence concerns the gene G6PD and G6PD deficiency.