Blood typing profile of a school-aged population of a North Togo township.

The aim of this study was the determination of hemoglobin (Hb) variants and ABO blood groups in a school population aged 6 to 9 years in the township of Agbandé-Yaka in North Togo. A cross-sectional study was carried out on 570 children of four primary schools at Agbande-Yaka, between March and July 2010. Hemoglobin characterization was done by alkaline buffer electrophoresis and the blood types ABO-Rhesus (Rh) D by immuno-hematological methods. A Hb variant was detected in 37.0% of the schoolchildren. Among them, the AS trait accounted for 11.9% and the AC trait for 20.2%. Homozygous Hb S (HBB: c.20A>T) was not found but Hb C (HBB: c.19G>A) appeared at a frequency of 3.3%, while compound heterozygotes carrying Hb SC were seen at a frequency of 1.6%. The O, B and A blood groups accounted for 49.0, 26.8 and 21.9%, respectively. The Hb anomalies reached a high prevalence in this school population. These results are remarkable by the absence of homozygous Hb S individuals compared to homozygous Hb C individuals, which were as numerous as expected. The frequencies of the ABO blood groups are similar to what has been found in other West African populations.