Hemoglobinopathies among five major ethnic groups in Karachi, Pakistan.

A brief survey of abnormal hemoglobin variants among the major ethnic groups of Karachi was conducted; 202,600 subjects were studied. Patients with low hemoglobin (Hb), low mean cell volume (MCV) and mean cell hemoglobin (MCH) including anemia, microcytosis, hypochromic hemolysis and target cells, were refered for the identification of hemoglobinopathy by molecular methods. Population screening showed that 60% had iron-deficiency anemia and 40% had hemolytic anemia, of which 20.6% was due to beta-thalassemia major, 13% beta-thalassemia trait, 5.1% sickle cell disease, 0.76% hemoglobin D Punjab (HbD Punjab), 0.32% hemoglobin C (HbC), and 0.22% hereditary persistence of fetal hemoglobin (HPFH).