The genetics of glucose-6-phosphate dehydrogenase deficiency

In the past 35 years, G-6-PD and its genetic variants have been a valuable resource for the geneticist and cell biologist. Over 380 putative variants have been described and have served as a paradigm, showing how many ways mutations can affect an enzyme. With the cloning and sequencing of G-6-PD, a new chapter has been opened in our understanding of G-6-PD. Variants that were thought to be different have proven to be identical, and those that were thought to be the same are now seen to be heterogeneous. Importantly, the ability to deduce quickly the amino acid substitution in a G-6-PD variant makes feasible, for the first time, the unraveling of relationships between the structure and function of this enzyme.