GSTM1 and anemia: On the other hand, a study by Prakash et al. found a higher prevalence of severe anemia, with 42% (n = 21) of patients having Hb < 6 gms%, 40% (n = 20) with moderate anemia (Hb 6-9 gms%), and 18% (n = 9) with mild anemia (Hb > 9 gms%) [18].