高通量基因拷贝数变异检测在前庭水管扩大诊断中的应用价值

Application value of high-throughput gene copy number variation detection in the diagnosis of enlarged vestibular aqueduct

目的探讨高通量基因拷贝数变异(CNV)检测在前庭水管扩大(EVA)诊断中的应用价值。方法设计一种基于双重连接和多重荧光PCR的高通量连接探针扩增(HLPA)分析方法,对2014年5月至2016年12月就诊于中南大学湘雅医院的46例非综合征型EVA患者行3个EVA相关基因(SLC26A4、FOXI1和KCNJ10基因)的拷贝数变异检测,用GeneMapper v4.1进行数据分析。对照组为100名听力正常,无其他遗传疾病的健康志愿者。结果共检测46例EVA患者,男32例,女14例,年龄1~26岁。在4例EVA患者中检测到SLC26A4基因1~3号外显子缺失(4/46,8.7%),该CNV在健康人群DGV(人类基因组结构变异数据库)以及文献中未见报道,且在100名正常对照中未检出。未检测到FOXI1和KCNJ10基因的拷贝数变异。结论本研究应用HLPA技术以EVA的已知基因为靶向区域进行CNV检测,是对耳聋基因点突变检测的补充,有助于实现EVA的精准基因诊断。

Objective To explore the application value of high-throughput gene detection method of copy number variations(CNV)in the diagnosis of enlarged vestibular aqueduct(EVA).Methods A total of 46 nonsyndromic hearing loss patients with EVA were recruited between May 2014 and December 2016 from Department of Otolaryngology of Xiangya Hospital,Central South University.A high-throughput multiplex analysis method based on double ligation and multiple fluorescent PCR was designed and performed to detect CNV in the three EVA-related genes(SLC26A4,FOXI1 and KCNJ10).The data were analyzed by GeneMapper v4.1.Healthy volunteers(n=100)were selected as normal controls.Results A total of 46 EVA patients were detected(32 males,14 females,aged 1 to 26 years).In 4 EVA patients,deletions of exons 1-3 of SLC26A4 gene(4/46,8.7%)were detected,which were not reported in the database of genomic variants(DGV),and were absent in 100 normal controls.There was no CNV detected in FOXI1 and KCNJ10 in the study.Conclusions In the current study,three known EVA-related genes were designed as the target area for CNV detection by high-throughput ligation-dependent probe amplification(HLPA)analysis.This method can be used as a supplementary analysis of point mutation detection of hearing loss,which helps achieve the accurate genetic diagnosis of EVA.