Certainly, Hb S variants (referred to as sickle cell trait in the heterozygous form and sickle cell disease in the homozygous form) and α-thalassemia have been detected among the Congolese population [9,10,38], which is not surprising given the frequency of these genotypes across sub-Saharan Africa [38]. This evidence concerns the gene GSTM1 and sickle cell disease.