PHENOTYPIC AND GENOTYPIC FREQUENCIES OF ABO AND RH(D)BLOOD GROUPS AMONG STUDENTS IN CHORORA SECONDARY AND PREPATATORYSCHOOL, WEST HARARGHE ZONE, OROMIA,ETHIOPIA

The Knowledge of distribution of ABO and Rh blood groups is helpful for effective management of blood banks and safe blood transfusion services. The frequency of these blood groups varies worldwide and may not be found in equal numbers even among ethnic groups. The aim of this study was to find out the distribution of ABO and Rh (D) blood groups among students attending Chorora Secondary and Preparatory school in West Hararghe Zone Oromio Ethiopia. The study was designed from January–March 2020 in the laboratory of study area.. Blood samples were taken from 422 (N = 422) volunteer students from finger-pricks and blood groups were determined on open slide by haemagglutination 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 (39%) followed by A (32%), B (23%) and AB the least (4.5%), in the pattern O > A > B > AB. Most of the students were found to be Rh+ (95%) and Rh- 4.5. Regarding the combined ABO/Rh blood groups, O+ was the most prevalent (161), A+ (129), B+ (93) and AB+ (18) and A- was also the most frequent 9(2.13%) B- 5(1.18%) and AB- 1(0.24%) among Rh-negative students. The allelic frequencies of O (r), A (p) and B (q), D and d were 0.3957 0.6291, 0207, 0.1500, 0.7768 and 0.3468, respectively. Genotypic frequency of IOIO was the most (0.3957) frequent while that of IBIB was the least (0.0232) while DD and dd were and 0.6034,0.2232 respectively. The observed and expected frequencies of individuals having ABO and Rh blood were not significantly different in both blood systems (goodness-of-f= 1 and χ2 for Rh = 7.6x10-12 , df = 1; P < 0.05). The present study gives vital information regarding the management of blood bank and transfusion services in the study community. These study was first document in the study area and evidence for other person who wants making research on phenotypic and genotypic frequency of ABO and Rh(D) blood system