GJB2 235delC纯合突变致聋患者的听力表型分析

Audiological Features in Patients with GJB2 c.235delC Homozygous Mutations

目的探讨GJB2 235del C纯合突变致聋患者的听力表型,着重分析其双耳听力对称性情况。方法 2007年至2014年间在解放军总医院聋病分子诊断中心筛查出的100例GJB2 235del C纯合突变的非综合征型耳聋患者,对其听力学表型及双耳听力对称性情况进行统计学描述。结果 100例患者的听力损失程度以极重度(51%)、重度(20%)和中重度(21%)常见。听力曲线图形以下降型(37%)和平坦型(21%)常见。100例患者中,图形或听力损失程度不对称的有61例,不对称性检出率为61%,其中包括:双耳听力曲线图形不对称(A型)36例,其中一耳为残余型听力或全聋者(Aa型)11例;规则性双耳听力损失程度不对称(B型)18例;不规则性双耳听阈不对称(C型)7例。听力不对称患者中,极重度听力损失21例(34.4%),重度听力损失17例(27.9%),中重度听力损失17例(27.9%);听力曲线图图形以下降型(36.1%)和平坦型(23.0%)最常见。听力对称患者中,极重度听力损失为30例(76.9%);听力图形以下降型(38.5%)和残余型(30.8%)最常见。结论 GJB2 235del C纯合突变致聋患者的双耳听力表型呈现多样性,且有较大比例的患者双耳听力不对称。

Objective The present study aims to characterize the audiological profile in patients with GJB2 c.235delC homozygous mutations,and specifically,the symmetry of bilateral hearing in each individual.Methods A total of 100 cases of GJB2 c.235delC homozygous mutations with NSHL diagnosed at the Chinese PLA General Hospital between 2007 and 2014 were analyzed in this study.Genetic tests,pure tone audiometry,and multiple-frequency auditory steady-state evoked responses(ASSR)tests were performed.Results Most of the cases presented with substantial hearing impairments.Hearing loss was profound in 51 cases,severe in 20 cases,and moderate to severe in 21 cases.Descending(37%)and flat(21%)audiogram types were common.Sixty-one out of the 100 cases showed asymmetrical hearing loss,of which 36 demonstrated audiogram curve asymmetry(Type A asymmetry)including unilateral residual hearing or total hearing loss in 11 cases(Type Aa),18 showed paralleled interaural differences(Type B asymmetry),and the remaining 7 showed irregular interaural differences(Type C asymmetry).In patients with asymmetric hearing,hearing loss was profound in 21 cases(34.4%),severe in 17 cases(27.9%),and moderate-to-severe in 17 cases(27.9%),with the descending(36.1%)and flat(23.0%)patterns being most common.In contrast,among the patients showing symmetric hearing,most(30 cases,76.9%)presented with severe hearing loss with descending(38.5%)or residual(30.8%)types of audiogram.Conclusions Patients with GJB2 c.235delC homozygous mutations-related hearing impairment demonstrate diverse phenotypes of hearing loss,with a substantial number of cases showing asymmetric hearing.