Study on the relationship between the pathogenic mutations of SLC26A4 and CT phenotypes of inner ear in patient with sensorineural hearing loss.

Lihua Wu,Yi Jiang,Shupin Tang,Pu Dai,Jianman Wu,Sheng Chen,Yunliang Liu

doi:10.1042/bsr20182241

Lihua Wu, Yi Jiang + Show 5 more

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https://doi.org/10.1042/bsr20182241

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Journal: Bioscience reports	Publication Date: Mar 22, 2019
Citations: 6	License type: CC BY 4.0

Affiliation: Fujian Medical University, Nanfang Hospital

Abstract

To investigate the possible association of pathogenic mutations of SLC26A4 and computerized tomography (CT) phenotypes of inner ear, and explore the feasibility of using the method of gene sequence analysis. A total of 155 patients with bilateral hearing loss carrying SLC26A4 gene mutations were further subjected to high-resolution temporal bone CT and thyroid B ultrasound tests. The potential relationship between the pathogenic mutations of gene and the CT phenotypes were analyzed. As a result, 65 patients (41.9%, 65/155) carried SLC26A4 gene mutations, and 27 cases were detected with pathogenic mutations of SLC26A4 where IVS7-2A>G (55.6%, 15/27) was the most common pathogenic mutation. Amongst them, 19 patients carrying bi-allelic SLC26A4 mutations were all confirmed to have inner ear malformation by CT scan including four cases of enlarged vestibular aqueduct (EVA) and 15 cases of Mondini dysplasia (MD). However, there was only one in eight cases of single allele pathogenic mutation who was confirmed to have EVA by CT scan. Further, only one patient with EVA was confirmed to be slightly higher of total T3 than normal by thyroid ultrasound scan and thyroid hormone assays. These findings suggested that CT detection and SLC26A4 gene detection are efficient methods to diagnose EVA, which can complement each other. Also, the bi-allelic pathogenic mutations of SLC26A4 are more likely to induce inner ear malformation than single allele pathogenic mutation.

Highlights

Congenital hearing impairment is the most common neurosensory disorder in humans, which is usually associated with abnormalities of inner ear structures
In order to improve the diagnosis of inner ear malformation in patients with Sensorineural hearing loss (SHL), we explored the relationship between the pathogenic mutation type of GJB2 SLC26A4 and computerized tomography (CT) phenotype based on sequencing all the exons of SLC26A4 gene of 155 deaf patients, and further analyzed the correlation of SLC26A4 mutations with thyroid function, and thyroid B ultrasound
We performed SLC26A4 gene mutation analysis in combination with inner ear imaging on deaf patients at Xiamen City Special Education School and found 12.9% (20/155) had Mondini dysplasia (MD) and isolated enlarged vestibular aqueduct (EVA) (IEVA)

Summary

Introduction

Congenital hearing impairment is the most common neurosensory disorder in humans, which is usually associated with abnormalities of inner ear structures. There still exists misdiagnosis or miss while in some cases of minor lesions, such as incomplete separation, cochlea axis and screen area malformations, due to the lack of high-resolution CT equipment and experienced imaging diagnostic physicians [2]. It is meaningfull to develop an alternative or complementary approach to improve the diagnosis of inner ear malformation. More than half of all cases of hearing impairment are caused by mutations in genes related to the hearing process [3]. Sensorineural hearing loss (SHL) is considered a monogenic disease in which the inactivation of one of the genes is enough to cause the disease [4]. It was reported that mutation in SLC26A4 was associated with the common causes of non-syndromic SHL

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