GENOTYPIC AND ALLELIC FREQUENCIES OF ABO AND RH (D) BLOOD GROUPS AMONG HARDIM SECONDARY SCHOOL STUDENTS IN GUBA KORICHA WOREDA, WEST HARARGHE ZONE, OROMIA REGIONAL STATE, ETHIOPIA

The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. The ABO and Rh blood groups varies worldwide and are not found in equal numbers even among ethnic groups. This study was aimed at getting information and document the frequencies of alleles, phenotypes and genotypes of ABO and Rh (D) blood group systems among Hardim secondary school students. The study was conducted in January 2022 in the laboratory of Hardim Health Center, Hardim. Blood samples were taken from 403 sampled volunteer students from finger-pricks and blood groups were determined on open slide by Haemaglutination method using commercially available anti-sera A, B, and Rh (D). Descriptive statistics was used to calculate percentage frequencies of blood phenotype, the genotypic and allelic frequencies of the blood groups were calculated from the observed phenotypes under the assumption of Hardy–Weinberg equilibrium. In the ABO blood grouping system, type O was the most prevalent (40.2%) followed by A (29%), B (24.3%) and AB the least (6.5%), in the pattern O > A > B > AB. Most of the students were found to be Rh+ (85.9%) and Rh- (14.1%). Regarding the combined ABO/Rh blood groups, O+ was the most prevalent (142), A+ (98), B+ (84) and AB+ (22) and A- was also the most frequent 19, B- 14 and AB- 4 among Rh-negative students. The allelic frequencies of O (r), A (p) and B (q), D and d were 0.6345, 0.1971, 0.1681, 0.627, and 0.373, respectively. Genotypic frequency of ���� was the most (0.4026) frequent while that of ����was the least (0.0283) while DD and dd were 0.397, 0.137 respectively. The observed and expected frequencies of individuals having ABO and Rh blood were significantly different in both blood systems (for ABO, X2= 0.0243345 with df =3; p < 0.05 and X2 for Rh = 0.00000599, df = 1; p < 0.05). The present study is supposed to give vital information regarding the management of blood bank and transfusion services in the study community. The study finding would also be used as baseline information for other researcher who would like to engage in similar studies in the area for the future.