Guo Chang, Huang Sha-Sha, Yuan Yong-Yi, Zhou Ying, Wang Ning, Kang Dong-Yang, Yang Su-Yan, Zhang Xin, Gao Xue, Dai Pu
College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing 100853, China.
National Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, China.
Neural Plast. 2020 Aug 1;2020:8841522. doi: 10.1155/2020/8841522. eCollection 2020.
Hereditary hearing loss is characterized by remarkable phenotypic heterogeneity. Patients with the same pathogenic mutations may exhibit various hearing loss phenotypes. In the Chinese population, the c.235delC mutation is the most common pathogenic mutation of and is closely related to hereditary recessive hearing loss. Here, we investigated the hearing phenotypes of patients with hearing loss associated with the homozygous c.235delC mutation, paying special attention to asymmetric interaural hearing loss. A total of 244 patients with the c.235delC homozygous mutation encountered from 2007 to 2015 were enrolled. The severity of hearing loss was scaled with the American Speech-Language-Hearing Association (ASHA). Auditory phenotypes were analyzed, and three types of interaural asymmetry were defined based on audiograms: Type A (asymmetry of hearing loss severity), Type B (asymmetry of audiogram shape), and Type C (Type A plus Type B). Of the 488 ears (244 cases) examined, 71.93% (351) presented with profound hearing loss, 14.34% (70) with severe hearing loss, and 9.43% (46) with moderate to severe hearing loss. The most common audiogram shapes were descending (31.15%) and flat (24.18%). A total of 156 (63.93%) of the 244 patients exhibited asymmetric interaural hearing loss in terms of severity and/or audiogram shape. Type A was evident in 14 of these cases, Type B in 106, and Type C in 36. In addition, 211 of 312 ears (67.63%) in the interaural hearing asymmetry group showed profound hearing loss, and 59 (18.91%) exhibited severe hearing loss, with the most common audiogram shapes being flat (27.88%) and descending (22.12%). By contrast, in the interaural hearing symmetry group, profound hearing loss was observed in 140 ears (79.55%), and the most common audiograms were descending (46.59%) and residual (21.59%). Hearing loss associated with the c.235delC homozygous mutation shows diverse phenotypes, and a considerable proportion of patients show bilateral hearing loss asymmetry.
遗传性听力损失的特点是具有显著的表型异质性。具有相同致病突变的患者可能表现出各种听力损失表型。在中国人群中，c.235delC突变是最常见的致病突变，与遗传性隐性听力损失密切相关。在此，我们调查了与纯合c.235delC突变相关的听力损失患者的听力表型，特别关注双耳不对称听力损失。共纳入了2007年至2015年期间遇到的244例c.235delC纯合突变患者。听力损失的严重程度采用美国言语-语言-听力协会（ASHA）的标准进行分级。分析听觉表型，并根据听力图定义了三种类型的双耳不对称：A型（听力损失严重程度不对称）、B型（听力图形状不对称）和C型（A型加B型）。在检查的488只耳朵（244例）中，71.93%（351只）表现为极重度听力损失，14.34%（70只）为重度听力损失，9.43%（46只）为中度至重度听力损失。最常见的听力图形状为下降型（31.15%）和平坦型（24.18%）。在244例患者中，共有156例（63.93%）在听力损失严重程度和/或听力图形状方面表现出双耳不对称听力损失。其中14例表现为A型，106例为B型，36例为C型。此外，双耳听力不对称组的312只耳朵中有211只（67.63%）表现为极重度听力损失，59只（18.91%）为重度听力损失，最常见的听力图形状为平坦型（27.88%）和下降型（22.12%）。相比之下，在双耳听力对称组中，140只耳朵（79.55%）表现为极重度听力损失，最常见的听力图为下降型（46.59%）和残留型（21.59%）。与c.235delC纯合突变相关的听力损失表现出多样的表型，相当一部分患者表现出双侧听力损失不对称。
