Study on rate gene mutation of β -thalassemia

Abstract

Objective To detect the rare gene mutation of β-thalassemia in Foshan area. Methods Basic erythrocyte hematologic parameters were performed through auto cell counter Sysmex XT2000i in routine for all 8400 patients who came to Foshan Maternal and Children's Hospital for prenatal screen. And Hb electrophoresis were carried out through auto analyzer Helena Spire 3000. Then identified the commonest known 17 types beta thalassemia mutations by reverse dot blot hybridization for the 3600 patients whose erythrocyte parameters were associated with hypochromia or whose electrophoresis results had elevated HbA2 or HbF or abnormal band. 1260 cases were identified as beta thalassemia. For the 45 doubtful patients who were not found the commonest known 17 types beta thalassemia mutations, direct DNA sequencing of the entire β-globin gene was performed. Results There were 45 patients were associate with hypochromiaand had elevated HbA2 or HbF or abnormal band who were not found the commonest 17 types beta thalassemia mutations by reverse dot blot hybridization. After sequencing the entire beta globin gene, 15 rare beta thalassemia gene mutations were found, of which 2 cases were nt-90 (C→T), 2 cases were CD6 (GAG→AAG), I case was IVS-I-116 (T→G), I case was IVS-I-128 (T→G), I case was IVS-I-130 (G→C), and 8 cases were CD113 (GTG→GAG). Conclusion Direct gene sequencing can be effective in identifying a rare beta thalassemia mutation and applying to prenatal diagnosis for thalassemia. Key words: Beta thalassemia; Rare; Gene mutation; Gene sequencing