Abstract：
Ring chromosomes (RCs) are a structural aberration that can be tolerated better in acrocentric or gonosomal chromosomes. Complete RCs arise from telomere-telomere fusions. Alternatively, genomic imbalances corresponding to the ends of the chromosomal arms can be seen with RC formation. RCs are unstable in mitosis, result in mosaicism, and are associated with a \"ring syndrome,\" which presents with growth and development phenotypes and differs from those features more frequently observed with pure terminal copy number changes. Due to variability in mosaicism, size, and genomic content, clear genotype-phenotype correlations may not always be possible. Given the rarity of RCs, this historical data is invaluable. We performed a retrospective review of individuals bearing RCs to investigate the incidence in our laboratory. This work details the methods and features seen in association with twenty-three autosomal RCs. In decreasing order, the most frequently seen autosomal RCs were 18, 22, 4, 13, 17, and 9. The additional cases detail clinical and cytogenomic events similar to those reported in RCs. As methodologies advance, insights may be gleaned from following up on these cases to improve genotype-phenotype correlations and understand the cryptic differences or other predisposing factors that lead to ring formation and development.
摘要：
环染色体（RCs）是一种结构畸变，可以在肢端或性腺染色体中更好地耐受。完整的RC来自端粒-端粒融合。或者，与染色体臂末端相对应的基因组失衡可以通过RC形成看到。RCs在有丝分裂中是不稳定的,导致马赛克，并与“环综合症”有关，“呈现生长和发育表型，与那些更频繁观察到的纯末端拷贝数变化的特征不同。由于镶嵌的可变性，尺寸,和基因组内容，明确的基因型-表型相关性可能并不总是可能的。鉴于RC的稀有性，这些历史数据非常宝贵。我们对携带RC的个体进行了回顾性审查，以调查我们实验室的发病率。这项工作详细介绍了与23个常染色体RCs相关的方法和特征。按递减顺序,最常见的常染色体RCs是18,22,4,13,17和9.其他病例详述了与RC中报道的相似的临床和细胞基因组事件。随着方法论的进步，从这些病例的随访中可能会收集到见解，以改善基因型与表型的相关性，并了解导致环形成和发育的潜在差异或其他诱发因素。
