Abstract
This study was conducted on 1409 Saudi males and females living in Makkah and Bisha areas in the Western Province of Saudi Arabia. to determine the frequency of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and hemoglobin S (Hb S) genes and to investigate interactions between the two genes. The frequency of severe G-6-PD deficiency was 0.055 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 identified included G-6-PD-A+. G-6-PD-A-. G-6-PD-Mediterranean and G-6-PD-Mediterranean-like with the frequencies 0.0288. 0.0026, 0.05497 and 0.1963, respectively in males and 0.0033, 0.0130. 0.0293 and 0.2696 respectively in the females in Makkah. In Bisha, the corresponding gene frequencies were 0.00436. 0.0.0767 and 0.0746 in males and 0.00570, 0, 0.05413 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.