A complex mosaicism of the short arm of chromosome 1 detected by SNP microarray analysis is described in a patient presenting a 4-Mb 1p36 terminal deletion and associated phenotypic features. The array pattern of chromosome 1p displayed an intriguing increase in divergence of the SNP heterozygote frequency from the expected 50% from the centromere towards the 1p36 breakpoint. This suggests that various overlapping segments of UPD were derived by somatic recombination between the 1p homologues. The most likely explanation was the occurrence of a series of events initiated in either a gamete or an early embryonic cell division involving a 1pter deletion rapidly followed by multiple telomere captures, resulting in additive, stepped increases in frequency of homozygosity towards the telomere. The largest segment involved the entire 1p, and at least four other capture events were observed, indicating that at least five independent telomere captures occurred in separate cell lineages. The determination of breakpoint position by detection of abrupt changes in B-allele frequency using a moving window analysis demonstrated that they were identical in blood and saliva, the tissues available for analysis. We developed a model to explain the interaction of parameters determining the mosaic clones and concluded that, while number, size, and position of telomere captures were important initiating determinants, variation in individual clone frequencies was the main contributor to mosaic differences between tissues. All previous reports of telomere capture have been restricted to single events. Other cases involving multiple telomere capture probably exist but require investigation by SNP microarrays for their detection.

中文翻译：

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洞察与端粒亚型缺失相关的复发性端粒捕获的机制和后果。

通过SNP基因芯片分析检测到的1号染色体短臂的复杂镶嵌术在患者中表现出4-Mb 1p36末端缺失和相关的表型特征。染色体1p的阵列模式显示出SNP杂合子频率从着丝粒的预期50％到1p36断裂点的差异显着增加。这表明UPD的各种重叠片段是通过1p同源物之间的体细胞重组而衍生的。最可能的解释是发生在配子或早期胚胎细胞分裂中的一系列事件的发生，这些事件涉及1pter缺失的迅速消失，随后是多个端粒的捕获，导致端粒纯合子频率的累加逐步增加。最大的细分市场涉及整个1p，并且观察到至少四个其他捕获事件，表明在独立的细胞谱系中发生了至少五个独立的端粒捕获。通过使用移动窗口分析检测B等位基因频率的突然变化来确定断点位置，这表明它们在血液和唾液（可用于分析的组织）中相同。我们开发了一个模型来解释确定镶嵌克隆的参数之间的相互作用，并得出结论，尽管端粒捕获的数量，大小和位置是重要的决定因素，但各个克隆频率的变化是造成组织之间镶嵌差异的主要因素。以前有关端粒捕获的所有报道均仅限于单个事件。