Haemoglobin electrophoresis showed 37 cases (78.7%) of homozygous HbSS, seven heterozygous (14.9%) Hb AS, 3 composite heterozygous: two cases (4.2%) of HbSC and one case of HbS-beta thalassemia (2.1%). The gene discussed is GSTM1; the disease is beta thalassemia.