贵州从江侗族和江口土家族人群β-地中海贫血基因突变型的研究

The Genotype distribution and characteristics of beta-thalassemia of the Dong and Tujia nationality in Guizhou Province

目的了解β-地中海贫血在贵州从江县侗族、江口县土家族中的基因类型特点、基因型频率及分布规律。方法采用抗碱血红蛋白(HbF)和血红蛋白A2(HbA2)定量测定对人群进行β-地中海贫血初筛,同时应用全自动血细胞分析仪进行RBC、Hb、HCT、MCV、MCH、MCHC、RDW等7项血液学指标分析,用常规酚-氯仿抽提法提取筛查阳性受检者DNA,经PCR-反向点杂交法对β珠蛋白基因进行突变分析。结果受检982人中,共检出52例β-地中海贫血携带者,总检出率为5.27%,其中侗族、土家族检出率分别为7.85%、2.68%;经β珠蛋白突变基因分析,在这两个民族中检出中国人常见3种突变类型:CD17(A→T)无义突变(39例,75.00%),CD41-42(TCTT)移码突变(12例,23.07%)和βE(Codon26)(1例,1.92%)。结论在贵州省少数民族中β-地中海贫血有很高的发病率,基因突变类型具有显著的民族特征,β珠蛋白基因变异情况很独特,可能与族内婚配、家族发病聚集性和通婚地域半径狭小有关。

Objective To investigate the incidence of β-thalassemia and the gene variations of beta-globin in Congjiang Dong and Jiangkou Tujia people in Guizhou. Methods Venous blood was sampled to determine the HbF and HbA2 by the AM-electrophoresis to screen out the heterogenotes of β-thalassemia, then the blood of heterogenotes were analyzed by the automatic blood cell analyzer, DNA was extracted from white blood cells with the routine method and analyzed by PCR and RDB （reverse dot blot） hybridization. Results Among the samples, the incidence of β-thalassemia carriers was 5.27%, gene mutation in these area were CD41-42 （TCTF） （ 12 cases, accounting for 23.07%） ,CD17 （A→T） （39 cases,accounting for 75.00% ） and β^E （ 1 cases, 1.92% ）.Conclusions The incidence of β-thalassemia is very high in the area and the unique beta-globin gene variations are different to that of the Chinese population, which might be related to the intra-ethnic marriage, the conglomerate family mobidity and the narrow marriage radius.