Abstract：
Background: The majority of small supernumerary marker chromosomes (sSMCs) are derived from one single chromosome. Complex sSMCs instead consist of two to three genomic segments, originating from different chromosomes. Additionally, discontinuous sSMCs have been seen; however, all of them are derived from one single chromosome. Here, we reported a 41 year-old patient with infertility, hypothyroidism, rheumatism, and degenerative spine and schizoaffective disorder, being a carrier of a unique, complex, and discontinuous sSMC. Methods: The sSMC was characterized in detail by banding and molecular cytogenetics including fluorescence in situ hybridization (FISH) and array-comparative genomic hybridization (aCGH), as well as by optical genome mapping (OGM). Results: The neocentric sSMC characterized here contained seven portions of five different chromosomes and was present in ~50% of both peripheral blood cells and buccal mucosa cells. aCGH and OGM revealed gains of 8q12.3q12.3, 8q22.3−8q23.1, 9q33.3−9q34.11, 14q21.1−14q21.1, 14q21.1−14q21.2, 15q21.2−15q21.2, and 21q21.1−21q21.1. Furthermore, glass-needle based microdissection and reverse FISH, as well as FISH with locus-specific probes confirmed these results. The exact order of the involved euchromatic blocks could be decoded by OGM. Conclusions: Among the >7000 reported sSMCs in the literature, this is the only such complex, discontinuous, and neocentric marker with a centric minute shape.
摘要：
背景：大多数小的超数标记染色体（sSMC）来自一个单染色体。相反，复杂的sSMC由两到三个基因组片段组成，来源于不同的染色体.此外,已经看到不连续的sSMC；然而，它们都来源于一条染色体。这里,我们报道了一名41岁的不孕症患者，甲状腺功能减退,风湿病,退行性脊柱和分裂情感障碍，作为一个独特的载体，复杂，和不连续的sSMC。方法：通过条带和分子细胞遗传学对sSMC进行详细表征，包括荧光原位杂交（FISH）和阵列比较基因组杂交（aCGH）。以及通过光学基因组作图(OGM)。结果：此处表征的新中心sSMC包含五个不同染色体的七个部分，并且存在于约50％的外周血细胞和颊粘膜细胞中。aCGH和OGM揭示了8q12.3q12.3、8q22.3−8q23.1、9q33.3−9q34.11、14q21.1−14q21.1、14q21.1−14q21.2、15q21.2−15q21.2和21q21.1−21q21.1的收益。此外，基于玻璃针的显微解剖和反向FISH，以及具有基因座特异性探针的FISH证实了这些结果。OGM可以解码所涉及的常色差块的确切顺序。结论：在文献中报道的>7000个sSMC中，这是唯一如此复杂的，不连续,和具有中心微小形状的新中心标记。
