摘要目的 评估利用微阵列-比较基因组杂交技术检测少量细胞非整倍体的准确率及相关影响因素.方法 结合10K 2.0单核苷酸多态性(SNP)基因分型芯片平台与多重置换扩增技术(MDA),计算并比较扩增模板为1～10个细胞时各染色体拷贝数分析的准确率,评估影响芯片平台的拷贝数准确率的有关因素及其对染色体拷贝数异常的实际分辨率.结果 使用MDA-DNA作参照时,拷贝数分析的准确率[(79.3±2.9)%～(100.0±1.7)%]高于使用gDNA作参照时的准确率[(66.7±3.4)%～(89.5±3.3)%](P<0.001).随着模板增加至10细胞,芯片可在1 M平滑化处理的同时获得94%的分析准确率.对于单细胞MDA产物,缺失型非整倍体具有比获得型非整倍体更高的分析准确率[1C组(71.9±4.1)%～(95.5～2.0)%;1C-sDel-4组(81.4±3.7)%～(99.6±2.8)%],各组间差异均有统计学意义(P<0.01).结论 10K 2.0 SNP基因分型芯片平台结合多重置换扩增技术可有效对少量细胞进行非整倍体检测,选择MDA-DNA作为参照是提高分析准确率的最关键因素,而增加细胞模板与提升分析中的平滑化参数(即降低芯片的分辨率要求)也有助于改善拷贝数准确率,在同样的条件下,芯片更容易准确检出缺失型非整倍体.

abstractsObjective To evaluate the accuracy and influencing factors in use of array-comparative genomic hybridization (CGH) combined with multiple displacement amplification (MDA) for aneuploidy screening in a small number of ceils.Methods 10K 2.0 SNP mapping array platform and MDA were used in combination to analyze the copy number concordance of MDA product from a small number of cell templates (1 - 10).Related factors that influenced the copy number concordance and the practical resolution of SNP array were then estimated.Results The copy number concordance was higher when MDA-DNA rather than gDNA was used as a reference [(79.3±2.9)%-(100.0±1.7)% vs (66.7±3.4)%-(89.5±3.3)%] (P<0.001).The copy number concordance along the whole genome was up to 94% when 10 cells were used as template under 1 M smoothing treatment.For MDA products from single cells, the concordance was higher for aneuploidy due to chromosome "loss" than for those due to chromosome "gain" [(71.9±4.1)%-(95.5±2.0)% in group 1C vs (81.4±3.7)%-(99.6±2.8)% in group 1C-sDel-4] (P<0.01).Conclusions 10K 2.0 SNP mapping array in combination with MDA is a reliable and highly efficient method for aneuploidy screening in a small number of cells.The use of MDA- DNA as reference, increasing the number of template cells and widening smoothing size can improve the copy number concordance.Accurate detection of a "loss" variation is more readily than as for a "gain" variation under the same condition.