Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
Genet Med. 2013 Jun;15(6):450-7. doi: 10.1038/gim.2012.152. Epub 2012 Dec 13.
Chromosomal microarray analysis enables the detection of microdeletions/duplications and has become the standard in clinical diagnostic testing for individuals with congenital anomalies and developmental disabilities. In the era of genomic arrays, the value of traditional chromosome analysis needs to be reassessed.
We studied 3,710 unrelated patients by chromosomal microarray analysis and chromosome analysis simultaneously and compared the results.
We found that chromosomal microarray analysis detected the chromosomal imbalances that were identified by chromosome analysis with the exception of six cases (0.16%) that had mosaic abnormalities. Of note, one case showed mosaicism for two abnormal cell lines, resulting in a balanced net effect and a normal chromosomal microarray analysis. Further structural abnormalities such as unbalanced translocations, rings, and complex rearrangements were subsequently clarified by chromosome analysis in 18% of the cases with abnormal chromosomal microarray analysis results. Apparently balanced rearrangements were detected by chromosome analysis in 30 cases (0.8%).
Our data demonstrate that although chromosomal microarray analysis should be the first-tier test for clinical diagnosis of chromosome abnormalities, chromosome analysis remains valuable in the detection of mosaicism and delineation of chromosomal structural rearrangements.
染色体微阵列分析能够检测微缺失/重复，已成为先天性异常和发育障碍患者临床诊断检测的标准。在基因组芯片时代，需要重新评估传统染色体分析的价值。
我们同时对 3710 名无亲缘关系的患者进行了染色体微阵列分析和染色体分析，并对结果进行了比较。
我们发现染色体微阵列分析除了 6 例（0.16%）存在嵌合体异常的患者外，能够检测到染色体分析所确定的染色体不平衡。值得注意的是，有 1 例表现为两种异常细胞系的嵌合体，导致平衡净效应和正常的染色体微阵列分析。随后，在染色体微阵列分析结果异常的 18%的病例中，通过染色体分析进一步明确了不平衡易位、环状染色体和复杂重排等结构异常。30 例（0.8%）患者通过染色体分析检测到明显平衡的重排。
我们的数据表明，尽管染色体微阵列分析应作为染色体异常临床诊断的一线检测方法，但染色体分析在检测嵌合体和描绘染色体结构重排方面仍然具有价值。
