45例少见β地中海贫血患者β球蛋白基因序列分析

Study on rare gene mutation of β -thalaesemia

目的研究佛山地区稀有β地中海贫血基因突变。方法对来佛山妇幼保健院产前检查的8400例患者进行血细胞和血红蛋白电泳常规筛查．对其中3600例血象异常怀疑β地中海贫血的患者行反向点杂交检测常见的17种突变，确诊1260例，然后对未发现常见突变的45例可疑患者扩增β球蛋白基因送公司直接基因测序。结果发现了15例稀有β地中海贫血，其中nt-90（C→T）、CD6（GAG→AAG）突变各2例，IVS—Ⅰ-116（T→G）、IVS—Ⅰ-128（T→G）、IVS—Ⅰ-130（G→C）突变各1例，CD113（GTG→GAG）突变8例。结论针对未发现常见17种β地中海贫血基因突变的可疑患者采用β球蛋白基因直接基因测序鉴定可以发现稀有突变，并为患者更好地提供产前基因诊断服务。

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 fur 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 Spife 3000. Then identified the commonest known 17 types beta thalassemia mutations by reverse dot blot hybridization for the 3600 patients whose erythroeyte parameters were associated with hypochromia or whose electrophoresis resuhs 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 hypochromia and 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）, leasewaslVS- Ⅰ -116 （T→G）, lcasewaslVS-Ⅰ-128 （T→G）, lcasewaslVS- Ⅰ - 130 （ G →C ）, and 8 cases were CD 113 （ GTG→ GAG ）. Conclusion Direct gene sequencing can be effective in identifying a rare beta thalassemia mutation and applying to prenatal diagnosis for thalassemia.