The frequency of glucose-6-phosphate dehydrogenase phenotypes and sickle cell gene in Al-Qassim.

This study was conducted in the Al-Qassim area located in the central province of Saudi Arabia in order to estimate the frequency of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and sickle cell genes (Hb S). Blood samples from 1,015 Saudi males and females were analyzed for hemoglobin types, G-6-PD phonotypes and G-6-PD levels. Only two cases heterozygous to Hb S (ie Hb AS) were identified and the frequency of Hb S gene was 0.000985. The normal G-6-PD was G-6-PD-B+ occuring at a frequency of 0.944 and 0.966 in the male and female population, respectively. Variants identified included G-6-PD-A+, G-6-PD-Mediterranean, G-6-PD-A-, and G-6-PD-Mediterranean-like at frequencies of 0.0164, 0.0282, 0.0023, 0.0094 in the males and 0.0068, 0.0085, 0, 0.0102 in the female population, respectively. The severe G-6-PD deficiency was due mainly to G-6-PD Mediterranean and only one male with G-6-PD-A- (0.0023) was identified. These results showed that Al-Qassim had the lowest frequency of Hb S and G-6-PD deficiency genes compared to all other regions of Saudi Arabia that have been screened thus far.