GSTM1 and hemoglobinopathy: In diseases associated with systemic hemolysis, including the hemolytic-uremic syndrome, immune-mediated hemolytic anemias, hemoglobinopathies, such as sickle cell disease and malaria, plasma levels of hemoglobin (Hb) increase, resulting in depletion of the Hb scavenging protein, haptoglobin.