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

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.