中国南方汉族健康人TATA结合蛋白基因三核苷酸重复变异研究

目的 研究中国大陆脊髓小脑性共济失调（spinocerebellar ataxias,SCA）17型（SCA17）的分布频率,以及南方汉族健康人群TATA结合蛋白（TATA-binding protein,TBP）基因CAG/CAA重复次数正常变异范围.方法 应用荧光聚合酶链反应（PCR）、毛细管电泳等技术,对已经排除了SCA1、2、3、6、7和齿状核-红核-苍白球路易体萎缩的67个常染色体显性遗传SCA家系的先证者、66例散发SCA患者及110名健康人进行TBP基因CAG/CAA重复次数分析.结果 南方汉族健康人群TBP基因CAG/CAA重复次数范围为26～43次,杂合频率为76.36%,共有14种等位基因.在一个散发SCA患者中发现TBP基因CAG/CAA重复次数为44次.结论 SCA17在中国内地为罕见的SCA亚型,南方汉族健康人群TBP基因常见的CAG/CAA重复次数为34和35次.

Research on the normal range of trinucleotide repeat of TATA-binding protein gene in Han nationality in southern China

Objective To study the frequency distribution of spinocerebellar ataxia type 17 in mainland China and the normal range of CAC/CAA repeats of TATA-binding protein (TBP) gene in Han population in southern China. Methods The CAG/CAA repeats of TBP gene were detected using fluorescence-PCR and capillary electrophoresis technique in 67 probands of autosomal dominant familial spinocerebellar ataxias (SCA) and 66 sporadic SCA patients without CAC repeat expansion at the SCA1, 2, 3, 6, 7 and dentatorubralpallidolluysian atrophy loci, and 110 healthy persons were used as controls. Results The size of normal alleles varied from 26 to 43 repeats. There were 14 alleles, heterozygosity was 76. 36%. 44 CAG/CAA repeats of TBP gene in a sporadic SCA patient was detected. Conclusions SCA17 is a rare subtype of SCA in China. The most common CAG/CAA trinucleotide repeat expansion of TBP gene has 34 and 35 repeats in Han population in southern China