CNV-seq技术在染色体核型分析平衡易位患者中的临床应用

Clinical application of CNV-seq technique in patients with balanced translocation of chromosome karyotype analysis

目的通过对比基因组拷贝数变异测序技术(CNV-seq)与染色体核型分析技术在染色体平衡易位中的应用效果,是否存在平衡易位断裂点的微缺失微重复,是否有致病基因,探讨二者联合应用的价值与意义。方法选取2016年1月—2020年7月于柳州市妇幼保健院生殖助孕中心遗传咨询和检查的进行染色体核型分析为平衡易位患者80例,进行CNV-seq技术检测,将二者的检测结果进行分析比较。结果在80例平衡易位标本中,CNV-seq技术检出显示,未检出异常65例,检出异常15例,其中缺失有4例,重复有11例。异常检出率为18.75%。其中14例异常不在平衡易位断裂点中,1例在平衡易位点中,缺失片段大小为0.34 Mb,该片段为多态性。15例异常病例中,1例有明确致病的缺失,2例是多态性,2例良性,10例临床意义不明。结论CNV-seq技术可检出<5 Mb的染色体变异,将染色体核型分析技术与CNV-seq技术联合应用,检测出是否有微缺失微重复,是否有致病基因,具有很好的临床应用价值。

Objective To discuss the value and significance of the combined application of genome copy number variation sequencing(CNV-seq)and chromosome karyotype analysis through comparing the application effect of the two technologies in balanced chromosometranslocation,clarifying whether there are microdeletion or microduplications at balanced translocation breakpoints,and illuminating whether there are pathogenic genes.Methods Totally 80 patients,from January 2016 to July 2020,who came to the Assisted Reproductive Centre in our hospital for genetic counseling and examination and were determined as balanced translocation patients through chromosome karyotype analysis were selected.CNV-seq was performed,and the two test results were compared.Results In 80 cases of balanced translocation specimens,CNV-seq results indicated that values of 65 cases were in normal range,and the results of 15 cases were abnormal with 4 cases of deletion and 11 cases of duplication.The abnormal detection rate was 18.75%.Among them,14 abnormalities were not in the breakpoint of the balanced translocation,and 1 case was in the balanced translocation.The size of the fragment deleted was 0.34 Mb,which was a polymorphism.Among the 15 abnormal cases,1 case had a definite pathogenic deletion,2 cases were polymorphisms,2 cases were benign,and the clinical significance of 10 cases were unclear.Conclusion CNV-seq can detect chromosomal mutations less than 5 Mb.The combined application of chromosome karyotype analysis technology and CNV-seq technology is of good clinical application value which can detect whether there are microdeletions and microduplications,and whether there are pathogenic genes.