导流杂交基因芯片技术在地中海贫血基因诊断中的应用价值

Application value of flow-through hybridization and gene chip technology in gene diagnosis of thalassemia

目的 分析导流杂交基因芯片技术(FHGC)在地中海贫血基因诊断中的应用价值,指导优生优育。方法 选取2020年1—12月荆门市第二人民医院门诊妇产科的1 996对孕期夫妻双方的血液初步筛查异常结果样本,安排孕妇行地中海贫血基因检测和血红蛋白电泳检测,为夫妻双方建立档案。采用全自动血细胞分析仪检测平均红细胞体积(MCV)和平均红细胞血红蛋白量(MCH)。α地中海贫血基因诊断采用跨越断点PCR法和PCR扩增法,β地中海贫血基因诊断采用PCR结合反向斑点杂交法,在同一基因芯片上采用FHGC测定其扩增产物。结果 1 996例孕妇中经铁剂治疗无效者100例,确诊72例地中海贫血者,阳性率为72.00%,占1 996例孕妇的3.61%(72/1 996)。其中,携带α地中海贫血基因29例,占40.28%(29/72),阳性检出率为1.45%;携带β地中海贫血基因40例,占55.56%(40/72),阳性检出率为2.00%;携带复合型地中海贫血基因3例,占4.17%(3/72),阳性检出率为0.15%。在29例α地中海贫血患者中,--SEA/αα19例(65.52%),阳性检出率为0.95%;-α/αα(3.7/4.2)7例(24.14%),阳性检出率为0.35%;-α3.7/-α4.2 3例(10.34%),阳性检出率为0.15%。在40例β地中海贫血患者中,CD 41-42 15例(37.50%),阳性检出率为0.75%;CD 17 10例(25.00%),阳性检出率为0.50%;IVS-II I-654 8例(20.00%),阳性检出率为0.40%;CD 43 3例(7.50%),阳性检出率为0.15%;CD 71-72 2例(5.00%),阳性检出率为0.10%;CD 27/28 1例(2.50%),阳性检出率为0.05%;βE 1例(2.50%),阳性检出率为0.05%。在3例α复合β地中海贫血患者中,1例(33.33%)-α/αα(3.7/4.2)复合CD 17,阳性检出率为0.05%;1例(33.33%)-α/αα(3.7/4.2)复合CD 41-42,阳性检出率为0.05%;1例(33.33%)-α/αα(3.7/4.2)复合IVS-II-654,阳性检出率为0.05%。结论 本研究获得了荆门市孕妇地中海贫血的常见突变基因型,对于指导荆门市地中海贫血孕妇遗传咨询和产前诊断,提高优生优育具有重要意义。

Objective To analyze the application value of flow-through hybridization and gene chip technology(FHGC) in gene diagnosis of thalassemia, direct prenatal and postnatal care.Methods From January to December in 2020, the abnormal blood samples of pregnant couples in Department of Obstetrics and Gynecology of the Second People’s Hospital of Jingmen City were selected, and the pregnant women were arranged to undergo thalassemia gene detection and hemoglobin electrophoresis, the records were established for pregnant couples.Automatic blood cell analyzer was used to detect mean corpuscular volume(MCV) and mean corpuscular hemoglobin(MCH).α thalassemia gene diagnosis was performed using gap-PCR and PCR amplification method, β thalassemia gene diagnosis was performed using PCR combined with reverse dot hybridization, FHGC was used to detect the amplification product of the same gene chip.Results Among 1 996 pregnant women, 100 pregnant women were ineffective with iron therapy, and 72 pregnant women were diagnosed as thalassemia, the positive rate was 72.00%, accounting for 3.61% of the 1 996 pregnant women(72/1 996). Among 72 pregnant women with thalassemia, 29 cases carried α thalassemia gene, accounting for 40.28%(29/72), and the positive detection rate was 1.45%;40 cases carried β thalassemia gene, accounting for 55.56%(40/72), and the positive detection rate was 2.00%;3 cases carried compound thalassemia gene, accounting for 4.17%(3/72), and the positive detection rate was 0.15%.Among 29 cases with α thalassemia, 19 cases(65.52%) carried-SEA/αα, the positive detection rate was 0.95%;7 cases(24.14%) carried-α/αα(3.7/4.2), the positive detection rate was 0.35%;1 case carried-α3.7/-α4.2(10.34%), the positive detection rate was 0.15%.Among 40 cases with β thalassemia, 15 cases carried CD 41-42(37.50%), the positive detection rate was 0.75%;10 cases carried CD 17(25.00%), the positive detection rate was 0.50%;8 cases carried IVS-II I-654(20.00%), the positive detection rate was 0.40%;3 cases carried CD 43(7.50%), the positive detection rate was 0.15%;2 cases carried CD 71-72(5.00%), the positive detection rate was 0.10%;1 case carried CD 27/28(2.50%), the positive detection rate was 0.05%;1 case carried βE(2.50%), the positive detection rate was 0.05%.Among 3 cases with α complex β thalassemia, 1 case(33.33%) carried-α/αα(3.7/4.2) combined with CD 17, the positive detection rate was 0.05%;1 case(33.33%) carried-α/αα(3.7/4.2) combined with CD 41-42, the positive detection rate was 0.05%;1 case(33.33%) carried-α/αα(3.7/4.2) combined with IVS-II-654, the positive detection rate was 0.05%.Conclusion This study obtained common gene mutations of thalassemia in pregnant women in Jingmen City, which is of great significance in guidance of genetic counseling and prenatal diagnosis of pregnant women with thalassemia in Jingmen City and improvement of eugenics.