FREQUENCIES OF ABO AND RH-D BLOOD GROUP PHENOTYPES, ALLELES AND GENOTYPES AMONG STUDENTS OF ENTICHO SECONDARY AND PREPARATORY SCHOOL, CENTRAL TIGRAY, ETHIOPIA

The ABO and Rh blood groups are the most frequently studied genetic markers in a large group of people. The present study was aimed at providing information on the frequency of ABO and Rh D blood groups phenotypes,alleles and genotypes among students of Enticho Secondaryand Preparatory School. A total of 422 students were selected randomly among the students of Enticho Secondary and Preparatory School. Blood samples were collected by Open Slide Test method from May to June 2018. The expected frequencies of the ABO and Rh alleles and genotypes were computed using the Hardy Weinberg equation. Blood group O, Rh-positive had the highest frequency while blood group AB, Rh-negative had the lowest frequency among the students. The frequency of the B-blood group (0.3175),was observed to be greater than the frequency of the A-blood group (0.2038).Among the ABO blood groups, the highest and the lowest frequency were observed for the O (0.4384) and the AB (0.0403), blood groups respectively. The frequency of the IB and IA alleles were found to be 0.1986 and 0.1306, respectively. The frequencies of the heterozygous genotypes IA I O and IB I O expected under the Hardy WeinbergPrinciple were 0.1756 and 0.2670, respectively while the frequencies of the corresponding homozygous genotypes IA I A and IB I B were 0.0172 and 0.0398 respectively. The Rh positive and Rh negative blood type had frequencies of 0.9716 and 0.0284 respectively. The D and the d alleles of the Rh blood group system had expected frequencies of 0.8315 and 0.1685respectively in the students of Enticho. The chi square test revealed that the studentes of Enticho is at Hardy Weinberg genetic equilibrium. Further study at molecular level would definitely reveal the degree of genetic proximity among the population