GLUCOSE-6-PHOSPHATE-DEHYDROGENASE DEFICIENCY AND SICKLE-CELL GENES IN2 REGIONS OF WESTERN SAUDI-ARABIA

This study was conducted on 1409 Saudi males and females living in Mak kah and Bisha areas in the Western Province of Saudi Arabia. to determ ine the frequency of glucose-6-phosphate dehydrogenase (G-6-PD) defici ency and hemoglobin S (Hb S) genes and to investigate interactions bet ween the two genes. The frequency of severe G-6-PD deficiency was 0.05 5 and 0.042 in males and females, respectively, from Makkah and 0.0767 and 0.0541 in males and females, respectively from Bisha. The normal enzyme was G-6-PD-B+ in both regions and the G-6-PD phenotypes identif ied included G-6-PD-A+. G-6-PD-A-. G-6-PD-Mediterranean and G-6-PD-Med iterranean-like with the frequencies 0.0288. 0.0026, 0.05497 and 0.196 3, respectively in males and 0.0033, 0.0130. 0.0293 and 0.2696 respect ively in the females in Makkah. In Bisha, the corresponding gene frequ encies were 0.00436. 0.0.0767 and 0.0746 in males and 0.00570, 0, 0.05 413 and 0.0855 in females. Heterozygous females were not detected. The main variant producing severe and mild G-6-PD deficiency were G-6-PD- Mediterranean and G-6-PD-Mediterranean-like, respectively. Sickle cell gene was identified at a frequency of 0.029 and 0.0866 in Makkah and Bisha, respectively, and no interaction between sickle cell and G-6-PD deficiency genes were encountered.