Liu Xue Zhong, Pandya Arti, Angeli Simon, Telischi Fred F, Arnos Kathleen S, Nance Walter E, Balkany Thomas
Department of Otolaryngology, University of Miami, Miami, Florida 33136, USA.
Ear Hear. 2005 Jun;26(3):361-9. doi: 10.1097/00003446-200506000-00011.
The aim of the present study was to characterize audiological profiles in patients with GJB2 deafness
We screened DNA from 399 individuals with nonsyndromic deafness for mutations in the connexin 26 gene (GJB2) by sequence analysis. A total of 77 (19%) of these deaf individuals were biallelic GJB2 mutations (either homozygous or compound heterozygous mutations) (GJB2 deafness). Using the audiological classification criteria of genetic deafness proposed by the European Workshop on Genetic Hearing Loss, we analyzed audiograms of these patients to characterize audiological features of the GJB2 deafness. In addition, we reviewed audiological data of 411 deafness cases from the literature providing details of audiological data (including 157 with GJB2 deafness).
All categories of hearing loss severity were found, with significant differences in the findings from GJB2 cases: 1 (4.5%) of 22 individuals with mild hearing loss, 10 (13.3%) of 75 with moderate loss, 14 (14.9%) of 94 with severe loss, and 52 (25%) of 208 with profound deafness (Chi-square test, 3 df, p = 0.016). 81.6% of patients with GJB2 mutations had severe to profound loss, 18.4% with mild to moderate loss (Chi-square test, p = 0.014). The 235delC mutation was always associated with profound deafness. The main audiogram shapes found were residual/sloping (72.7%) and flat (23.4%). There were no differences in the severity and audiogram shapes of the hearing impairment between homozygous and compound heterozygous GJB2 deafness (Chi-square test, p > 0.05).
Our study shows that the probability of finding biallelic GJB2 mutations increases with the severity of hearing loss. Audiograms associated with GJB2 deafness were usually nonspecific. Patients with unknown causes of severe or profound hearing loss should be routinely tested for GJB2 mutations, but due to the variability in hearing loss, individuals with lesser degrees of hearing loss should not be precluded from testing.
本研究旨在描述GJB2耳聋患者的听力学特征。
我们通过序列分析对399例非综合征性耳聋患者的DNA进行筛查，以检测连接蛋白26基因（GJB2）的突变。这些耳聋个体中共有77例（19%）存在双等位基因GJB2突变（纯合或复合杂合突变）（GJB2耳聋）。我们采用欧洲遗传性听力损失研讨会提出的遗传性耳聋听力学分类标准，分析这些患者的听力图，以描述GJB2耳聋的听力学特征。此外，我们还回顾了文献中411例耳聋病例的听力学数据，这些文献提供了详细的听力学数据（包括157例GJB2耳聋患者）。
发现了所有类型的听力损失严重程度，GJB2病例的结果存在显著差异：22例轻度听力损失患者中有1例（4.5%），75例中度听力损失患者中有10例（13.3%），94例重度听力损失患者中有14例（14.9%），208例极重度耳聋患者中有52例（25%）（卡方检验，自由度为3，p = 0.016）。81.6%的GJB2突变患者存在重度至极重度听力损失，18.4%的患者存在轻度至中度听力损失（卡方检验，p = 0.014）。235delC突变总是与极重度耳聋相关。发现的主要听力图类型为残余/斜坡型（72.7%）和平坦型（23.4%）。纯合和复合杂合GJB2耳聋患者的听力损害严重程度和听力图类型没有差异（卡方检验，p > 0.05）。
我们的研究表明，发现双等位基因GJB2突变的概率随听力损失的严重程度增加。与GJB2耳聋相关的听力图通常是非特异性的。原因不明的重度或极重度听力损失患者应常规检测GJB2突变，但由于听力损失的变异性，不应排除听力损失程度较轻的个体进行检测。
