G6PD and G6PD deficiency: The second most common polymorphism found in this study was the Viangchan variant; 36% (13/36) of healthy G6PD deficient S'tieng, 9% (2/23) of healthy G6PD deficient Kinh and 22% (18/82) of Kinh with haemoglobinuria (35.4% with G6PD deficiency and 2.9% without).