Glucose-6-phosphate dehydrogenase deficiency: molecular heterogeneity in southeast Asian countries.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is common in malaria endemic regions and is estimated to affect more than 400 million people worldwide. Deficient subjects are mostly asymptomatic but clinical manifestations range from neonatal jaundice due to acute hemolytic anemia to chronic non-spherocytic hemolytic anemia. To date, biochemical parameters allowed more than 400 different G6PD variants to be distinguished thereby suggesting a vast genetic heterogeneity. So far, only a small portion of this heterogeneity has been confirmed at the DNA level with the identification of about 90 different point mutations in the G6PD coding sequence. To determine the molecular background of G6PD deficiency in Southeast Asian countries, we conducted molecular analyses of G6PD patients from the Philippines, Malaysia, Singapore, Vietnam and Indonesia. The most prevalent mutation identified differs from country to country, thus suggesting independent mutational events of the G6PD gene.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in Yogyakarta and its surrounding areas.

Glucose-6-phosphate dehydrogenase (G6PD) is one of the enzymes needed by the erythrocyte to generate ATP from ADP. Deficiency of this enzyme can lead to hemolysis of red blood cells. Being a malaria endemic area, Indonesia possibly has a high incidence of G6PD deficiency. It is estimated that 2-6% of the population are carriers. In 1996, we detected 145 neonates with G6PD deficiency using the formazan ring method. Among the males, 6.2% had moderate and 1.4% had low enzyme activity; females had enzyme activity in the normal range. Using the Sigma kit, Tashimi et al in 1995 examined 111 neonates in Yogyakarta, none of which was identified as "deficient". There was no correlation between erythrocyte hemolysis and G6PD enzyme content. Interestingly, using the same Sigma kit. Soro et al in 1994 found that among 134 individuals of Batak descent, 10 males (43.48%) and 9 females (8.11%) were G6PD deficient. These were similar to the results reported by Pramuji et al in 1995 for the people around Palembang. Since the G6PD gene is located on the X chromosome, this is a peculiar result thus further studies need to be done. In cooperation with Harvard University, Sumantri et al in 1995 described 14% as carriers. Molecular analysis among these 16 Javanese males showed the following mutations--nt563 (C->T) in 5 cases, nt1376 (G->T) in 3 cases, nt487 (G->A) in 2 cases, nt1311 (C->T) in 1 case with the remaining variants unknown.