PREVALENCE AND MOLECULAR CHARACTERIZATION OF GLUCOSE-6-PHOSPHATE DEHYDROGENASE (G6PD) DEFICIENCY IN FEMALES FROM PREVIOUSLY MALARIA ENDEMIC REGIONS IN NORTHEASTERN THAILAND AND IDENTIFICATION OF A NOVEL G6PD VARIANT

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common X-linked enzymopathy, highly prevalent in areas where malaria is or has been endemic. Prevalence of G6PD deficiency and characterization of G6PD variants in females from previously malaria endemic areas of northeast Thailand remain unstudied. Methods: Prevalence of G6PD deficiency was determined by a fluorescent spot test (FST) and multiplex allele specific (AS)- and restriction fragment length polymorphic (RFLP)-PCR developed for detection of common G6PD variants in the Thai population. Results: Prevalence of G6PD deficiency in female samples (n = 355) was 18% by FST and 27% by PCR-based genotyping. The most common variant was G6PD Viangchan (54%), followed by G6PD Canton (11%) and G6PD Union (11%); in addition, a novel heterozygous variant, G6PD Khon Kaen (c.305T>C, p.F102S located in the coenzyme-binding domain), was identified. The majority (75%) of G6PD activities of heterozygotes were within the intermediate deficiency range (30-80% of median normal enzyme activity). Conclusion: High prevalence of G6PD deficiency was present in females from northeast Thailand, the majority being due to heterozygosity of G6PD variants. The findings will have a bearing on an inclusion of primaquine in antimalarial-based policies for malaria elimination in populations with high prevalence in G6PD deficiency.