Abstract:
Frequencies of ABO and Rh-D blood groups vary worldwide and are not found in equal
numbers even among different ethnic groups. Some variations may even occur within one
ethnic group in different geographical areas. Therefore, this study was conducted to
determine the frequencies of ABO and Rh-D blood group phenotypes, alleles and
genotypes among Students of Oromo, Amhara, Argoba and Somali ethnic groups in
Mechara Secondary and Preparatory School,West Hararghe, Oromia. A total of 449
students were purposely selected among school Students and tested for ABO and Rh-D
blood groups antigens. Blood groupings were done using open slide method. The
frequencies of ABO and Rh-D blood groups phenotypes were expressed in percentages
and the modified Hardy-Weinberg Law was used to determine allele and genotype
frequencies whereas Chi-square test was used to compare observed phenotypic frequency
distribution of ABO and Rh-D blood groups with that expected under the HardyWeinberg
law . In the overall sample, the observed O, A, B, and AB blood group
percentages were 42.1%, 29.2%, 20.48% and 8.24%, respectively. The Rh-D positive
incidence was 98.84%, while Rh-D negative was 1.34% in the overall sample. The order
of ABO blood group allele frequencies were IO > IA > IB
in the overall samples and in
each of the four ethnic groups. The allele frequencies of IO
, IA
, and IB
in the total sample
were found to be 0.64, 0.21 and 0.16 respectively. The allele frequencies were 0.64 IO
, 0.22 IA
and 0.14 IB
for Oromo, 0.66 IO
, 0.19 IA
and 0.15 IB
for Amhara, 0.61 IO
, 0.20 IA
and 0.19 IB for Argoba and 0.63 IO
,0.22IA
,0.15 IB
for Somali ethnic groups. The Rhesus
blood group allele frequencies of the total sample were 0.884 D and 0.116 d.. There were
no significant differences among ethnic groups in blood type frequencies.
