The ABO and Rhesus groups in the north of Nigeria.

ABO and Rhesus blood group data were analysed from 43187 blood donors belonging to 34 ethnic groups, predominantly from northern Nigeria. This is the largest series to be reported on from the whole of West Africa. Group O was found in 46.6% of all those examined, but the numbers varied from 33.13% to 64.35% in different ethnic groups. Group A was found in 23.05% and Group B in 25.95%, but again there was much variation in the distribution of the blood groups in different ethnic groups. There was an overall frequency of 3.64% of Rhesus negatives, ranging from 1.4% to 8.72% in different ethnic groups. The results provide basic but useful information concerning many ethnic groups whose blood groups have not previously been reported.