The Hb D-Punjab variant had been reported in both heterozygous and homozygous states as well as in combination with other abnormal hemoglobins such as thalassemia or Hb S. Hb D-Punjab heterozygotes and homozygotes, the rarest form of inheritance, presented no clinical or hematological alterations, but occasionally manifested mild to moderate hemolytic anemia. This evidence concerns the gene GSTM1 and thalassemia.