【摘要】 目的　调查广西柳州市城镇人口中α和 β地中海贫血 (地贫 )的发生率和基因突变类型及其构成比。方法　以整群抽样收集 10 2 8份其父母双方或一方为柳州市户口的新生儿脐带血及1312份柳州市户口的婚检育龄成人的外周静脉血 ,分别进行α地贫和 β地贫调查 ;所有样品均进行红细胞 (RBC)参数和血红蛋白 (Hb)电泳分析 ,以巴特血红蛋白 (HbBart’s)阳性者为α地贫 ,平均红细胞体积 (MCV) <85fl和HbA2 ≥ 4 .0 %为 β地贫阳性表型指标。采用基于PCR的基因分析方法进行α和 β地贫及 β地贫复合α地贫样品的确诊 ,对α或 β地贫表型阳性而未查出基因者 ,以家系成员的表型分析诊断。结果　 10 2 8份脐带血样品中检出α基因携带者 112例 (包括 3例双重杂合子 ) ,α地贫基因携带率 11.19% ,共检出含 5种α地贫的等位基因 ,其构成比依次为 37.4 % ( SEA)、31.3%( α3.7)、17.4 % ( α4 .2 )、12 .1% (αCSα)和 0 .9% (αQSα)。 1312份成人外周静脉血样品中共发现 β地贫携带者 89例 ,基因携带率为 6 .78%。其中有 14例伴有胎儿血红蛋白 (HbF)增高 ,检出率 1.0 7%。在 89例 β地贫阳性样品中 ,有 16例 (占 18% )为 β地贫复合α地贫双重杂合子 ,共发现 9种不同的基因型 ,检出率为 1.2 2 %。该地区 3种最常见的基?更多还原

【Abstract】 Objective To investigate the gene frequencies and mutation patterns of α thalassemia(α thal) and β thalassemia(β thal) in Liuzhou city of Guangxi Zhuang Autonomous Region. Methods Cluster sampling was used. A total of 1 028 of umbilical blood samples were collected for a prevalence study of α thal and a total of 1 312 healthy young people when reciving pre marriage consultation were recruited for a β thal prevalence survey. Individuals live in city or town area of Liuzhou. A complete blood count as well as hemoglobin electrophoresis analysis were done in all of samples for phenotyping of α and β thals. Those with Hb Bart’s for α thal indicator and those with both microcytosis (MCV<85 fl) and elevated levels of Hb A 2 (≥4.0%) for β thal were further studied by DNA analysis. PCR based methodologies were used to characterize the mutation contributions of α and β thals. All the subjects were tested for the state of carrying β thala alleles for evaluating the situation of the compound heterozygotes of α thal with β thal. Results Of 1 028 random samples of umbilical blood screened, 112 of subjects were defined to be the gene carriers of α thal. The α thal carrier rate was as high as 11.19 % including 3 compound heterozygotes. Five well known types of α thal alleles were detected with gene contributions of 37.4 % ( SEA deletion ), 31.3 % ( α 3.7 deletion), 17.4 % ( α 4.2 deletion), 12.1 % (α CS α mutation), and 0.9 % (α QS α mutation), successively. Of the 1 312 adult specimens studied, 89 with β thal including 14 of the compound higher Hb F subjects were detected. All of the 89 phenotypic β thal carriers had the mutations in the beta globin gene, making the overall prevalence 6.78 %. The commonly seen three mutations,β CD41 42 ( CTTT) frameshieft,β CD17(T A) nonsense mutation and β 28 (A G) promoter variation were accounted for 90% of the β thal alleles in Liuzhou. Of these β thal subjects, 16 (accounting for 18% ) were found to be the compound heterozygosity for a β thal and an α thal with 9 different types of gene defects with a detection rate 1.22 %. Conclusion Data from ecidation of α and β thal gene frequencies and mutation spectrum in Liuzhou city was useful for genetic counselling and prenatal diagnosis of this disease.更多还原