GSTM1 and beta thalassemia: Besides with red cell parameters (MCV 67±8 vs. 90±5 fl, p<0.0001; Hb 12.5±1.6 vs. 14.7±1.3 g/dl, p<0.0001), the beta-thalassemia trait, detected in 22 patients (10%), was associated with higher ferritin (531, 132–858 vs. 252, 131–568, p = 0.01), TS (38±10 vs. 33±12%, p = 0.03), lower H/F (2, 1–12 vs. 7, 2–18×103, p = 0.019), and hepatic iron accumulation (15/23, 65% vs. 66/193, 34%, p = 0.005).