广西地区缺失型α地中海贫血基因分布特征

Gene distribution characteristics of deletional α-thalassemia in Guangxi region

目的 分析广西地区缺失型α地中海贫血（地贫）检出情况及基因分布特征,为基因诊断与遗传咨询提供理论依据.方法 采用跨越缺U PCR检测中国人群3种常见缺失型α地贫基因（-SEA、-α37、-α4.2）突变情况,对于常规地贫检测基大型与临床表型不相符的标本,采用多重连接探针扩增及α或β珠蛋白基大测序技术检测基因突变情况.分析广西地区缺失型α地贫的基因分布特征.结果 51 191名疑诊地贫者中,共检出缺失型α地贫19 853例,占39.9％,其中中国人群常见缺失型（--SEA、-α3 7、-α4.2）19 780例,泰国型缺失61例,三联体（香港型）（αααHK）9例,21.9 kb缺失1例及809 bp缺失2例.结论 广西地区缺失型α地贫所占比例高,类型复杂多样,对于基因型与临床表型不符的人群,进一步基因诊断可能检出罕见类型的地贫基因型,避免漏诊误诊,更好的为临床遗传咨询和产前诊断提供依据.

Objective To analyze the detection rate and gene distribution characteristic of deletional ct-thalassemia in Guangxi area, and to provide theoretic basis for thalassemia gene diagnosis and genetic counseling. Methods The regular gene diagnosis of 3 types of a-thai （-SEA、-α37、-α4.2） was performed by gap-PCR, multiple ligation probe and gene sequencing for globin ct or 13 were used to detect those samples whose genotype and phenotype were not consistent. And the distribution characteristic of α-thalassemia gene in Guangxi area was then analyzed. Results Out of 51 191 suspected thalassemia patients, there were 19 853 cases of deletional a-thalassemia, accounted for 39.9% in total positive rate, including 19 780 cases of regular types （-SEA、-α37、-α4.2）, 61 cases of Thailand-type deletion, 9 cases of triplet type （Hong Kong） （αααHK）, 1 case of 21.9 kb deletion type and 2 cases of 809 bp deletion type. Conclusion Types of deletional a-thalassemia were complex and accounted for large proportion in Guangxi area. Special gene diagnoses were needed for those couples whose genotype and phenotype were not consistent, in order to provide reliable basis for genetic counseling and prenatal diagnosis.