Molecular basis of p(CCG)n repeat instability at the FRA16A fragile site locus.
Molecular basis of p(CCG)n repeat instability at the FRA16A fragile site locus.
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FRA16A 脆弱位点基因座 p(CCG)n 重复不稳定性的分子基础。
DOI：
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发表时间：
1995
影响因子：
3.5
通讯作者：
Robert I. Richards
中科院分区：
文献类型：
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作者：
J. Nancarrow;K. Holman;Marie Mangelsdorf;Tada;M. Denton;G. Sutherland;Robert I. Richards
罕见的叶酸敏感脆弱位点是三核苷酸 p(CCG)n 重复序列不稳定扩展的结果，这些重复序列通常在拷贝数上具有多态性。在不同种族人群之间观察到脆弱位点 FRA16A p(CCG)n 重复等位基因的数量和频率存在差异，这表明某些等位基因可能倾向于不稳定。序列分析表明，较长且可变的等位基因与重复中断的丢失相关。因此，完美的重复配置似乎是与脆弱位点发生相关的不稳定性的必要先决条件。
Rare, folate-sensitive fragile sites are the result of the unstable expansion of trinucleotide p(CCG)n repeats, which are normally polymorphic in copy number. Differences in the number and frequency of alleles of the fragile site FRA16A p(CCG)n repeat were observed between different ethnic populations suggesting that certain alleles might be predisposed to instability. Sequence analysis demonstrated that the longer and more variable alleles were associated with loss of repeat interruption. Perfect repeat configuration therefore appears to be a necessary precondition for the instability associated with fragile site genesis.