Characterization of glucose-6-phosphate dehydrogenase in Thailand - The occurrence of 6 variants among 50 G-6-PD deficient Thai

Abstract

Characterization of partially purified eryrhrocyte G-6-PD from 50 enzymedeficient males in 45 unrelated Thai families revealed 6 enzyme variants. Thirty-five subjects in 31 families had G-6-PD variant with normal electrophoretic mobility, slightly low Km G-6-P, normal substrate-analog utilization, normal pH-optimum curve, and slightly increased heat stability. This enzyme variant is called G-6-PD Mahidol. Six subjects had enzyme with fast electrophoretic mobility (106-108% of normal), low Km G-6-P, slightly increased substrate-analog utilization, biphasic pH-optimum curve, and slightly low to normal heat stability. This variant was identical to G-6-PD Canton. Five subjects had G-6-PD with fast electrophoretic mobility (103-106% of normal), low Km G-6-P, very high substrate-analog utilization except for DPN which it did not use as cofactor, markedly biphasic pH-optimum curve and very low heat stability. This variant is called G-6-PD Union (Thai). Two brothers had G-6-PD with normal electrophoretic mobility, low Km G-6-P, slightly increased substrate-analog utilization, biphasic pH-optimum curve and low heat stability. This variant is designated G-6-PD Siriraj. G-6-PD from one patient had slightly fast electrophoretic mobility, increased substrateanalog utilization, especially of DPN, and very low thermal stability. It is called G-6-PD Kan. One subject had G-6-PD with normal electrophoretic mobility, Km G-6-P, pH-optimum curve and heat stability, and increased substrate-analog utilization. This G-6-PD variant is named G-6-PD Anant. G-6-PD Mahidol is far more common than any other known variants in Thailand. © 1973 Springer-Verlag.