Determination of allelic, phenotypic, and genotypic frequency of the distribution of ABO and Rh blood groups among Injibara University students, Ethiopia

Aim: The aim of the current study is to determine the allelic, phenotypic, and genotypic frequencies of the ABO and Rh (D) blood type distributions among Injibara University students. Method and Materials: Blood samples from 800 volunteer students were taken on 1st January 2024. A cross-sectional study design was performed. ABO and Rh (D) typing was done by antigen-antibody agglutination test using commercially available and standard anti-sera. Descriptive statistical measures on phenotypic frequency of ABO and Rh (D) blood types were described in simple percentages using SPSS version 26. The allelic and genotypic frequencies of the ABO and Rh blood groups were estimated using the assumption of Hardy-Weinberg equilibrium. Results: The ABO and Rh (D) blood phenotypes, respectively, were found to be O (37.5%) > A (32.5%) > B (23.8%) > AB (6.3%) and Rh+ (96.6%) > Rh- (3.4%) and the combined ABO and Rh(D) blood groups were in the order O+ (36.4%) > A+ (31.5%) > B+ (22.9%) > AB+ (5.8%) and O- (1.1%) >A- (1.0%) > B- (0.9%) > AB- (0.5%). The allelic frequencies of the ABO blood group of r (IO), p (IA), and q (IB) were 0.612, 0.22, and 0.16, respectively (IO > IA > IB). The allelic frequencies for ID = 0.816 and for Id = 0.184 were found. The genotypic frequency of IOIO was the most frequent (0.38) while that of IBIB was the least frequent (0.07). Whereas, IDID was most frequent (0.67) and dd was the least frequent (0.034). The observed and expected frequencies of individuals having ABO blood group showed no significant difference (x2 = 1.566, df = 3; P < 0.05), and Rh (D) blood phenotypes of individuals were not significantly different (x2 = 0.0225, df = 1; P < 0.05), which fits Hardy-Weinberg assumptions. Conclusion: The results of the survey showed that the O blood group was the most common, followed by A and B. The blood groups with the largest percentages in this study are O Rh+ (36.4%) and A Rh+ (31.5%), whereas the groups with the lowest ratios are AB Rh- (0.5%) and B Rh- (0.9%). The result and data obtained in the present study might be used as input for other scholars on safe blood transfusion practices in different regions of Ethiopia in the future.