G6PD Molecular Biology

The cloning of the gene for G6PD and the sequencing of its DNA have permitted the identification of mutations that cause G6PD deficiency.

More than 400 G6PD variants have been identified, a finding that explains the numerous biochemical and clinical phenotypes that have been described. Most mutations that result in enzymic deficiency are missense mutations  in the coding region. Both G6PD A− and G6PD Mediterranean represent mutant enzymes that differ from the respective normal variants by a single amino acid. Large deletions or frameshift mutations have not been identified, suggesting that complete absence of G6PD activity is likely lethal.