GSTM1 and thalassemia: Other α-thalassemia genotypes encountered included α0-thalassemia trait (n = 44), α+-thalassemia trait (n = 26), homozygous Hb CS or compound heterozygous Hb CS/Hb Pakse’ (n = 14), Hb CS trait (n = 12), Hb H disease (n = 7), Hb H-CS or Hb H-Pakse’ disease (n = 6), double heterozygous for α+-thalassemia/Hb CS (n = 5), homozygous α+-thalassemia (n = 4), Hb H-Quong Sze (n = 1) and four unknown α-thalassemia.