In our clinical practice, in a geographical area of high prevalence of thalassemia, we have noted that patients with alpha-thalassemia intermedia like Hb H disease or Hb H-Constant Spring (CS) disease seem to have higher prevalence of cardiovascular diseases or metabolic syndrome than that in normal population or even in beta-thalassemia patients. This evidence concerns the gene GSTM1 and hemoglobin H disease.