ABO and rhesus blood groups system in Tlemcen population, West Algerian

62 Abstract : On a sample of more than eleven thousand individuals residing in the wilaya of Tlemcen, we have determined the frequencies of blood groups A,B,O, rhesus plus and rhesus minus and the frequencies of the gene of these two systems A, B, O, D and d. Differences in phenotypic and genic frequencies have been revealed between the population Tlemcen town (urban area) it self on one side and five villages (rural area) surrounding it on the other (see geographical card). In fact, in the population of Tlemcen town, the frequencies of the phenotypes A, B, AB, O, rhesus plus and rhesus minus are respectively : 39.28 %; 12.84 %; 3.84 %; 44.04 %; 97.17% and 2.83 %. In rural area (the five villages together), these frequencies are respectively : 32.13 %; 15.68 %; 4.98 %; 47.21 %; 96.4 % and 3.60 %. And as for the frequencies of the genes A, B, O, D and d, they are respectively equal to : 0.2460; 0.0873; 0.6635; 0.8319 and 0.1681 in the population of the town to Tlemcen and as for what concerns the population of the Dairas, the frequencies of these genes are respectably equal to : 0.2070; 0.1093; 0.6870; 0.8103 and 0.1897. The causes of these differences are discussed.