Distribution of ABO and Rhesus Blood Group Alleles in the Tiv Ethnic Group of Benue State

Population-level data on ABO and Rhesus (Rh) blood group allele distribution are critical for blood transfusion services, paternity testing, and population genetics studies. The Tiv people of Benue State, North Central Nigeria, are one of the largest ethnic groups in the country, yet population genetic data specific to this group remain sparse. This study determined the ABO and Rh blood group distribution and estimated allele frequencies in a sample of the Tiv ethnic group from Benue State. A descriptive cross-sectional study enrolled 500 adult Tiv participants from four local government areas using multi-stage sampling. Blood grouping was performed using the tile agglutination method with commercially sourced antisera (anti-A, anti-B, and anti-D). Hardy-Weinberg equilibrium was tested, and allele frequencies for IA, IB, and IO were estimated. Findings indicated that blood group O was the most prevalent, followed by groups A, B, and AB. The Rh-positive phenotype was predominant, with Rh-negative occurring at a frequency comparable to sub-Saharan African reference populations. The data contribute to the National Blood Transfusion Service database and provide genetic reference data for the Tiv population. Keywords: ABO blood group, Rhesus factor, Tiv ethnic group, Benue State, allele frequency