Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked hereditary 
disease that predisposes red blood cells to oxidative damage. G6PD deficiency is 
particularly prevalent in historically malaria-endemic areas. Use of primaquine 
for malaria treatment may result in severe hemolysis in G6PD deficient patients. 
In this study, we systematically evaluated the prevalence of G6PD deficiency in 
the Kachin (Jingpo) ethnic group along the China-Myanmar border and determined 
the underlying G6PD genotypes. We surveyed G6PD deficiency in 1770 adult 
individuals (671 males and 1099 females) of the Kachin ethnicity using a G6PD 
fluorescent spot test. The overall prevalence of G6PD deficiency in the study 
population was 29.6% (523/1770), among which 27.9% and 30.6% were males and 
females, respectively. From these G6PD deficient samples, 198 unrelated 
individuals (147 females and 51 males) were selected for genotyping at 11 known 
G6PD single nucleotide polymorphisms (SNPs) in Southeast Asia (ten in exons and 
one in intron 11) using a multiplex SNaPshot assay. Mutations with known 
association to a deficient phenotype were detected in 43.9% (87/198) of cases, 
intronic and synonymous mutations were detected alone in 34.8% (69/198) cases 
and no mutation were found in 21.2% (42/198) cases. Five non-synonymous 
mutations, Mahidol 487G>A, Kaiping 1388G>A, Canton 1376G>T, Chinese 4 392G>T, 
and Viangchan 871G>A were detected. Of the 87 cases with known deficient 
mutations, the Mahidol variant was the most common (89.7%; 78/87), followed by 
the Kaiping (8.0%; 7/87) and the Viangchan (2.2%; 2/87) variants. The Canton and 
Chinese 4 variants were found in 1.1% of these 87 cases. Among them, two females 
carried the Mahidol/Viangchan and Mahidol/Kaiping double mutations, 
respectively. Interestingly, the silent SNPs 1311C>T and IVS11nt93T>C both 
occurred in the same 95 subjects with frequencies at 56.4% and 23.5% in tested 
females and males, respectively (P<0.05). It is noteworthy that 24 subjects 
carrying the Mahidol mutation and two carrying the Kaiping mutation also carried 
the 1311C>T/IVS11nt93T>C SNPs. Further studies are needed to determine the 
enzyme levels of the G6PD deficient people and presence of additional G6PD 
mutations in the study population.