Tsukada Keita, Fukuoka Hisakuni, Usami Shin-Ichi
Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto City, Japan.
Audiol Neurootol. 2015;20(3):147-52. doi: 10.1159/000368292. Epub 2015 Mar 25.
Mutations in the GJB2 gene have been of particular interest as it is the most common causative gene for congenital deafness in all populations. Detailed audiological features, including genotype-phenotype correlations, have been well documented. However, in spite of abundant gene as well as protein expression in the vestibular end organs, neither vestibular symptoms nor vestibular functions have yet been elucidated. In the present study, vestibular functions were evaluated in patients diagnosed with GJB2-related deafness.
Vestibular functions were evaluated by caloric test and cervical vestibular evoked myogenic potential (cVEMP) testing in 24 patients with biallelic GJB2 mutations.
Twenty-one of 23 patients (91.3%) had normal caloric responses and significantly lower cVEMP amplitudes than the control subjects. In the patients who were able to undergo vestibular testing, the mostly normal reactions to caloric testing indicated that the lateral semicircular canal was intact. However, the majority of GJB2 patients showed low cVEMP reactions, indicating a saccular defect.
GJB2基因的突变一直备受关注，因为它是所有人群中先天性耳聋最常见的致病基因。详细的听力学特征，包括基因型与表型的相关性，已有充分记录。然而，尽管在前庭终器中有丰富的基因和蛋白质表达，但前庭症状和前庭功能尚未阐明。在本研究中，对诊断为GJB2相关耳聋的患者进行了前庭功能评估。
对24例双等位基因GJB2突变患者进行冷热试验和颈前庭诱发肌源性电位（cVEMP）测试，以评估前庭功能。
23例患者中有21例（91.3%）冷热反应正常，cVEMP振幅明显低于对照组。在能够进行前庭测试的患者中，对冷热测试大多正常的反应表明外侧半规管完整。然而，大多数GJB2患者cVEMP反应较低，表明球囊存在缺陷。
