Prevalence of Hemoglobin E Among the Children Taking Regular Blood Transfusion at the Day Care Room, Yangon Children Hospital, Myanmar
Peripheral blood of 132 children (73 boys and 59 girls; nine months to 12 year old; Bamar, Kayin, Mon, Rakhine, Shan, Chin ethnic groups), who had been clinically diagnosed as thalassemia major and were taking frequent and regular blood transfusion at the day care room, Yangon Children Hospital, Myanmar. Before blood transfusion, blood sample was collected in EDTA as an anticoagulant and examined red cell morphology and total Hb level for the diagnosis of anemia. The hemolysate was prepared from the red cells and subjected for anion-exchange high perfomance liquid chromatography (DEAE-HPLC) and isoelectric focusing (IEF) to detect and analyze different Hb present. Eighty four out of 132 samples (63.6%) showed large peak in DEAE-HPLC and thick clear band in IEF representing the presence of Hb E. Being not separated, Hb A2 was also included in the concentration of Hb E calculated from chromatogram. The presence of Hb E was confirmed by βE globin gene detection of a restriction enzyme (Mnl I) assay of PCR products obtained from the genomic DNA. Since Hb E prevalence was found to be very high in this study, accurate determination of Hb A2 was important for the carrier screening in Myanmar thalassemia and more importantly Hb E should be included as the most common mutant in a protocol for an effective prenatal diagnosis program in Myanmar.