基因组拷贝数变异测序与染色体核型分析在胎儿遗传学诊断中的比较

Comparison of CNV-seq and karyotyping analysis in fetal genetic diagnosis

摘要:

目的比较基因组拷贝数变异测序(CNV-seq)技术和染色体核型分析和在产前胎儿遗传学诊断中的应用价值。方法收集来我院有产前诊断指征进行羊水穿刺的259例孕妇,取材后,送检染色体核型分析和CNV-seq,比较两种方法在产前诊断中的优缺点。结果259例标本中,共诊断异常染色体核型及微缺失微重复23例,总阳性诊断率8.88%(23/259),CNV-seq结果显示,共有22例染色体拷贝数异常(12例三体+9例微缺失微重复+1例三倍体),检出率为8.49%;染色体核型分析结果显示为:17例染色体异常(12例三体+3例结构异常+1例嵌合型+1例三倍体),检出率为6.56%。此外还检出染色体多态7例。结论CNV-seq与染色体核型分析对于染色体非整倍体的检测效力一致,CNV-seq能检测染色体微缺失微重复,染色体核型分析则能诊断出三体具体核型,在怀疑性染色体异常时,建议行两者联合检测。

关键词:基因组拷贝数变异测序;染色体核型分析;遗传学诊断

Abstract:

【Objective】To compare the application value of copy number variation sequencing(CNV-seq)technique and chromosome karyotype analysis in prenatal fetal genetic diagnosis.【Methods】G-banding karyotyping and copy number variation sequencing(CNV-seq)were simultaneously performed on 259 women with indications of prenatal diagnosis who were collected for subjecting to amniocentesis during middle pregnancy.The values of the two methods were compared in prenatal diagnosis.【Results】Twenty-three cases both karyotype and CNV abnormality were detected in total 259 cases,the total abnormal diagnosis rate was 8.88%.Among them,there were 22 copy number variations(trisomy 12,microdeletions and microduplications 9,triploid 1),CNV abnormal rate was 8.49%(22/259),there were 17 cases of chromosome abnormality(trisomy 12,structural chromosome aberration 3,chromosomal mosaicism 1,triploid 1),the chromosomal abnormal rate was 6.56%(17/259).In addition,7 cases of chromosome polymorphism were also detected.【Conclusion】CNV-seq and karyotyping analysis have the same efficacy in the detection of chromosome aneuploidy,submicroscopic microdeletions/microduplications can be detected by CNV-seq,the specific type of trisomes was determined by karyotyping.It is recommended to combine karyotype analysis and CNV-seq for detection of sex chromosome abnormality.

Key words:copy number variation sequencing(CNV-seq);karyotyping analysis;genetic diagnosis