Small supernumerary marker chromosomes (sSMCs) are rare structural abnormalities in the population; however, they are frequently found in children or fetuses with hypoevolutism and infertile adults. sSMCs are usually observed first by karyotyping, and further analysis of their molecular origin is important in clinical practice. Next-generation sequencing (NGS) combined with Sanger sequencing helps to identify the chromosomal origins of sSMCs and correlate certain sSMCs with a specific clinical picture. Karyotyping identified 75 sSMCs in 74,266 samples (0.1% incidence). The chromosomal origins of 27 of these sSMCs were detected by sequencing-related techniques (NGS, MLPA and STR). Eight of these sSMCs are being reported for the first time. sSMCs mainly derived from chromosomal X, Y, 15, and 18, and some sSMC chromosomal origins could be correlated with clinical phenotypes. However, the chromosomal origins of the remaining 48 sSMC cases are unknown. Thus, we will develop a set of economical and efficient methods for clinical sSMC diagnosis. This study details the comprehensive characterization of 27 sSMCs. Eight of these sSMCs are being reported here for the first time, providing additional information to sSMC research. Identifying sSMCs may reveal genotype-phenotype correlations and integrate genomic data into clinical care.

中文翻译：

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75 例具有小额外标记染色体的患者的基因型-表型相关性。

小的多生标记染色体（sSMCs）是人群中罕见的结构异常；然而，它们经常出现在发育迟缓的儿童或胎儿和不育成人中。sSMCs 通常首先通过核型分析来观察，进一步分析其分子起源在临床实践中很重要。新一代测序 (NGS) 与 Sanger 测序相结合有助于识别 sSMC 的染色体起源，并将某些 sSMC 与特定的临床表现相关联。核型分析在 74,266 个样本中鉴定出 75 个 sSMC（发生率 0.1%）。通过测序相关技术（NGS、MLPA 和 STR）检测了其中 27 个 sSMC 的染色体起源。其中 8 个 sSMC 是首次报道。sSMCs 主要来源于染色体 X、Y、15 和 18，一些 sSMC 染色体起源可能与临床表型相关。然而，其余 48 例 sSMC 病例的染色体起源尚不清楚。因此，我们将开发一套经济有效的临床sSMC诊断方法。本研究详细介绍了 27 个 sSMC 的综合表征。其中 8 个 sSMC 是首次在此报告，为 sSMC 研究提供了更多信息。识别 sSMC 可以揭示基因型-表型相关性并将基因组数据整合到临床护理中。其中 8 个 sSMC 是首次在此报告，为 sSMC 研究提供了更多信息。识别 sSMC 可以揭示基因型-表型相关性并将基因组数据整合到临床护理中。其中 8 个 sSMC 是首次在此报告，为 sSMC 研究提供了更多信息。识别 sSMC 可以揭示基因型-表型相关性并将基因组数据整合到临床护理中。