GSTM1 and anemia (phenotype): This was confirmed by the routine hematological analysis, which showed significantly decreased MCV and MCH indicating microcytic hypochromic anemia (Table 1), together with abnormal hemoglobin presenting as an overlapping peak of Hb A2 and Hb O-Arab (92.5%), an Hb F peak (6.4%) and an uncharacterized Hb X peak (1.1%), but without the Hb A peak (Figure 3A).