中国汉族人群SCA1、2、3、6、7、8、10、12、17亚型和齿状核-红核-苍白球-路易体萎缩亚型频率分布

目的 研究中国汉族人群中脊髓小脑性共济失调(SCAs)不同基因亚型的频率分布.方法 运用聚合酶链反应、变性聚丙烯酰胺凝胶电泳、Southern blot、T载体克隆重组DNA技术结合直接测序等技术对559例临床诊断为SCA的患者(363例常染色体显性遗传先证者,196例散发患者)进行了SCA1、SCA2、SCA3/MJD、SCA6、SCA7、SCA8、SCA10、SCA12、SCA17和齿状核-红核-苍白球-路易体萎缩(DRPLA)致病基因多核苷酸病理重复突变检测分析.结果 在363个常染色体显性遗传的SCA(AD-SCA)家系中,发现有15个SCA1家系(4.13%),26个SCA2家系(7.16%),187个SCA3/MJD家系(51.52%),6个SCA6家系(1.65%),7个SCA7家系(1.93%),1个SCA12家系(0.28%)和1个SCA17家系(0.28%),120个SCA家系未明确基因分型(33.06%);在196例散发SCA患者中,发现有2例SCAI患者(1.02%),3例SCA2患者(1.53%),15例SCA3/MJD患者(7.65%),3例SCA6患者(1.53%),173例SCA患者未明确基因分型(88.27%);未发现SCA8、SCA10和DRPLA型患者.结论 在中国汉族人群中SCA3/MJD为最常见的SCA亚型,其次为SCA2、SCA1、SCA7和SCA6,SCA12和SCA17比较少见,SCA8、SCA10和DRPLA罕见,SCA17亚型为国内首次报道.部分AD-SCA家系存在其他致病基因的作用,大部分散发SCA患者除遗传因素外还存在其他致病因素.

Frequency of spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, 12, 17 and dentatorubral-pallidoluysian atrophy in Chinese Han population

Objective To assess the frequency of different subtype of spinocerebellar ataxias (SCAs) in Chinese Han population. Methods The nueleotide repeat mutations of SCA1, SCA2, SCA3/ MJD, SCA6, SCAT, SCA8, SCA10, SCA12, SCA17 and dentatorubral-pallidoluysian atrophy (DRPLA) were detected by the polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis (PAGE), Southern blot, recombinant DNA technology by T-vector cloning and direct sequencing technique in a cohort of 559 Mainland Chinese patients affected by spinocerebellar ataxia, including 363 families with autosomal dominant SCA (AD-SCA) and 196 sporadic cases. Results Among the 363 AD-SCA families, 15 families (4. 13%) were positive for SCA1, 26 (7. 16%) for SCA2, 187 (51.52%) for SCA3/MJD, 6 (1.65%) for SCA6, 7 (1.93%) for SCA7, 1 (0. 28%) for SCA12 and 1 (0. 28%) positive for SCA17; 120(33. 06%) were negative for all the tested SCAs. There were 2 (1.02%) SCAI, 3 (1.53%) SCA2, 15 (7. 65%) SCA3/MJD, 3 (1.53%) SCA6 and 173 (88.27%) not identified in the 196 sporadic SCA patients. None of the SCA8, SCA10 and DRPLA mutation was found. Conclusions SCA3/MJD is a substantially common subtype of AD-SCAs and sporadic SCA in Chinese Han patients with SCAs, subsequently followed by SCA2, SCA1, SCAT and SCA6; SCA12 and SCA17 are uncommon subtypes, while SCA8, SCA10, and DRPLA are rare, if not absent. SCA17 subtype was initially identified in mailand China. Some other genes might be causative in those unidentified AD-SCA pedigrees, and other etiological factors besides genetic cause might contribute for those sporadic cases.