The decreased levels of HCT, RBC, and Hb observed in our study could be attributed to chronic haemolysis, reduced red cell survival, and a diminished response of erythropoietin related to SCA [41, 42], whereas the high MCV and RDW-CV are consistent with poikilocytosis and reticulocytosis as a consequence of the bone marrow compensatory mechanism in response to the anaemia stress. The gene discussed is GSTM1; the disease is anemia (phenotype).