Yu S, Fiedler S D, Brawner S J, Joyce J M, Zhou X G, Liu H Y
Department of Pathology, Children's Mercy Hospitals and Clinics, Kansas City, MO 64108, USA.
Cytogenet Genome Res. 2012;136(1):6-14. doi: 10.1159/000334271. Epub 2011 Nov 23.
Fourteen cases with constitutional small supernumerary marker chromosomes (sSMCs) were assessed by combination of diverse techniques including genome-wide high-resolution chromosomal microarray (CMA), chromosome banding analysis (G banding), fluorescence in situ hybridization (FISH), and quantitative real-time PCR (qPCR). Of the 14 sSMCs, 4 were complex sSMCs composed of genomic materials from more than one chromosome, 7 were simple sSMCs which contain only centromeric and/or pericentromeric regions from individual chromosomes, and the remaining 3 sSMCs contained inverted duplications. CMA precisely defined the breakpoints and genetic contents in 12 of the 14 sSMCs but failed to identify 2 of the 14 sSMCs due to lack of detectable euchromatin. In addition, CMA revealed unexpected genomic abnormalities in 2 cases. FISH techniques were necessary for the determination of the physical location, structure, formation mechanism, mosaic level, and origin of all these sSMCs. Our data emphasize the necessity to combine these methods for comprehensive characterization of sSMCs.
采用包括全基因组高分辨率染色体微阵列（CMA）、染色体显带分析（G显带）、荧光原位杂交（FISH）和定量实时PCR（qPCR）等多种技术相结合的方法，对14例携带体质性小额外标记染色体（sSMC）的病例进行了评估。在这14条sSMC中，4条是由来自一个以上染色体的基因组材料组成的复杂sSMC，7条是仅包含单个染色体着丝粒和/或着丝粒周围区域的简单sSMC，其余3条sSMC包含反向重复序列。CMA精确确定了14条sSMC中的12条的断点和遗传内容，但由于缺乏可检测的常染色质，未能识别出14条sSMC中的2条。此外，CMA在2例病例中发现了意外的基因组异常。FISH技术对于确定所有这些sSMC的物理位置、结构、形成机制、嵌合水平和起源是必要的。我们的数据强调了将这些方法结合起来对sSMC进行全面表征的必要性。
