Population variation analysis at nine loci containing expressed trinucleotide repeats
Population variation analysis at nine loci containing expressed trinucleotide repeats
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DOI：
10.1046/j.1469-1809.1997.6150425.x
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发表时间：
1997-09-01
影响因子：
1.9
通讯作者：
Novelletto, A
中科院分区：
文献类型：
--
作者：
Jodice, C;Giovannone, B;Novelletto, A
对来自三大洲的4个群体的9个CAG重复序列基因座的多态性进行了研究。根据疾病相关扩展或CAG中断的存在与否，对它们的正常变异进行了跨群体或在座位子集中的分析。所有群体中所有座位的等位基因分布的一个统一特征是显著的非正态分布。在有已知扩展的座位上观察到的等位基因数、平均长度、长度范围和重复数的变异显著大于未扩展的座位。与不中断(CAG)n基序相比，在有(CAG)n基序的基因座上发现了更长的等位基因。这9个基因座检测到的群体间变异性水平与其他基因座相当。总的来说，这些数据与假设常染色体表达的三核苷酸只通过插入/缺失单个单位来累积变异的模型是不一致的。
The polymorphisms of nine loci containing reiterated CAG repeats were examined in four populations from three continents. Their normal variation was analysed across populations or in subsets of loci grouped according to either the presence/absence of disease-associated expansions or CAG interruptions. A unifying feature of the allele distributions of all loci in all populations was the marked non-normality. Significantly larger numbers of alleles, average lengths, length ranges and variances in repeat number were observed in loci with vs. without known expansions. Significantly longer alleles were found at loci with vs. without interruption of the (CAG)n motif. The nine loci detected levels of inter-population variability comparable to other loci. Altogether the data are at odds with a model assuming that autosomal expressed trinucleotides accumulate variation exclusively by insertion/deletion of a single unit.