Relatively mild anemia with Hb at 9.9±0.8 g/dl and MCV of 82.8±8.5 fl and lower Hb A2 level (1.4 ± 0.2%) as compared to heterozygous Hb CS (2.1 ± 0.2%) were observed for 9 cases with homozygous Hb CS. The gene discussed is GSTM1; the disease is anemia.