FREQUENCIES OF ABO AND Rh(D) BLOOD GROUP ALLELES AMONG STUDENTS OF BORA SECONDARY SCHOOL, BORA WOREDA, EAST SHOA ZONE, OROMIA REGION, ETHIOPIA

ABO and Rh blood groups vary worldwide and are not distributed uniformly even among related ethnic groups. The study was aimed at having information on the allelic frequency, genotypic frequency of ABO and Rh blood group phenotypes among the students of Bora Secondary School. From a total of 719 students 240 voluntary participant students were `selected for this study. Among them, 134 (55.83%) were males and 106(44.17%) were females. Blood samples were collected by pricking the middle finger and a drop of each antisera; anti A, anti B and anti D, were added and mixed with each blood sample and rocked gently for 60 sec to observe agglutination. There are differences in frequency distribution of the blood group (ABO) among the students. Hardy–Weinberg method was used to determine allelic frequencies and SPSS software was used for the data processing. Chi-square test was done to check whether the population was at Hardy-Weinberg genetic equilibrium based on ABO and Rh blood group phenotypes. In this study the most prevalent blood group was type O (40 %) followed by A (31.25 %), B (22.5 %), and AB (6.25 %). The most prevalent Rh-Positive blood groups among students were type O + (37.92 %) followed by A + (30 %), B+ (20 %), and AB+ (5.42 %). Similarly the highest frequency in Rh-Negative blood groups among students was type O - (6.25 %) followed by B - (2.083%), A - (1.25 %), and AB- (0.83) blood group. Blood group AB and Rh-negative were least frequency among the students of Bora Secondary School. The distribution of allelic frequency was 0.2097 for I A , 0.1561 for I B and 0.6342 for I O this occurred in the order of I O > IA> IB . The allelic frequency of blood group O was the highest in the sample population and the genotypic frequencies were 0.4022 (I O I O ), 0.04397 (I A I A ), 0.2659 (I A I O ), 0.02437 (I B I B ), 0.1973(I B I O ) and 0.06546 (I A I B ). Over all, the genotype of blood group I O I O blood group was the highest.