单侧大前庭水管综合征：临床特征、SLC26A4突变及ASNR波形的诊断价值

文献信息

中文摘要

背景： 单侧大前庭水管综合征（EVAS）是一种临床上隐匿的疾病，其病因及与常见双侧表型的关系尚未充分明确。
目的： 探讨单侧EVAS的临床和分子遗传学特征，以提高诊断准确性和听力损失预防策略。
方法： 我们回顾性分析了2例单侧EVAS患儿的临床、听力学、影像学和遗传学数据，并汇总了10项研究的遗传学资料。
结果： 病例1为10岁男孩，右耳突发性听力损失，携带SLC26A4复合杂合变异（c.919-2A > G；c.1003T > C）。病例2为8岁男孩，右耳偶然发现听力损失，听性脑干反应（ABR）测试显示声诱发短潜伏期负反应（ASNR）。两例均显示患耳内淋巴管和囊的单侧扩大。各研究报告的频率差异很大：复合杂合变异为4%至10%，单杂合变异为8%至62.5%。
结论： 单侧EVAS表现出异质性的听力学特征和遗传背景。对于通过听力筛查但携带SLC26A4突变的患者，尤其是那些携带单杂合变异者——这在临床实践中常见——临床医生应警惕单侧EVAS的可能性。

英文摘要

Background: Unilateral enlarged vestibular aqueduct syndrome (EVAS) is a clinically insidious condition, and its aetiology and relationship to the common bilateral phenotype remain insufficiently characterised. Objectives: Explore the clinical and molecular genetic characteristics of unilateral EVAS to improve diagnostic accuracy and hearing loss prevention strategies. Methods: We retrospectively reviewed clinical, audiological, imaging, and genetic data from two paediatric patients with unilateral EVAS, and compiled genetic profiles from 10 studies. Results: Case 1, a 10-year-old boy with sudden hearing loss of the right ear, harboured compound heterozygous SLC26A4 variants (c.919-2A > G; c.1003T > C). Case 2, an 8-year-old boy with incidental hearing loss of the right ear, exhibited an acoustically evoked short-latency negative response (ASNR) on auditory brainstem response (ABR) testing. Both cases showed unilateral enlargement of the endolymphatic duct and sac in the affected ear. Reported frequencies varied considerably across studies: compound heterozygous variants from 4% to 10%, and single heterozygous variants ranged from 8% to 62.5%. Conclusions: Unilateral EVAS presents with heterogeneous audiological profiles and genetic backgrounds. In patients who pass the hearing screening but harbor SLC26A4 mutations, particularly those with single heterozygous variants-a frequent observation in clinical practice-clinicians should remain vigilant to the possibility of unilateral EVAS.