Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy.
University of Trieste, Department of Medicine, Surgery and Health Sciences, Trieste, Italy.
Hear Res. 2019 Sep 15;381:107769. doi: 10.1016/j.heares.2019.07.006. Epub 2019 Jul 13.
Hearing loss (HL), one of the most common congenital disorder, affects about one child in 1000. Among the genetic forms of HL, ∼30% of the cases are associated with other signs or symptoms, leading to Syndromic Hearing Loss (SHL) with about 700 different forms described so far. In this report, we refer the clinical and molecular data of 38 Italian SHL unrelated patients, and their relatives, affected by the most common syndromes associated with HL (i.e., Usher, Pendred, Charge, Waardenburg, Alport, Stickler, Branchiootorenal and Microdeletions syndromes). Patients have been analysed using next-generation sequencing (NGS) and High Density (HD)-SNP array technologies. Data analysis led to the identification of nine novel and 27 known causative mutations in 12 genes and two microdeletions in chromosomes 1 and 10, respectively. In particular, as regards to Usher syndrome, that affects 32% of our patients, we were able to reach a molecular diagnosis in 83% of the cases and to identify in Northern Eastern Italy a very common USH2A gene mutation (39%) (c.11864G > A, p.(Trp3955*) which can be defined "Central-Eastern European allele." As regards to Alport syndrome, we were able to potentially reclassify a pathogenic allele in the COL4A3 gene, previously associated only with benign familial hematuria. In all the other cases, the genomic analysis allowed us to confirm the role of known causative genes and to identify several novel and known alleles. Overall, our results highlight the effectiveness of combining an accurate clinical characterization with the use of genomic technologies (NGS and SNP arrays) for the molecular diagnosis of SHL, with a clear positive impact in the management and treatment of all the patients.
听力损失(HL)是最常见的先天性疾病之一,每 1000 名儿童中就有 1 名受到影响。在 HL 的遗传形式中,约 30%的病例与其他体征或症状相关,导致目前已描述了约 700 种不同形式的综合征性听力损失(SHL)。在本报告中,我们参考了 38 名意大利 SHL 非相关患者及其亲属的临床和分子数据,这些患者受最常见的与 HL 相关的综合征(即 Usher、Pendred、Charge、Waardenburg、Alport、Stickler、Branchiootorenal 和微缺失综合征)影响。患者使用下一代测序(NGS)和高密度(HD)-SNP 阵列技术进行分析。数据分析确定了 12 个基因中的 9 个新的和 27 个已知的致病突变以及染色体 1 和 10 上的两个微缺失。特别是对于影响我们 32%患者的 Usher 综合征,我们能够在 83%的病例中达到分子诊断,并在意大利东北部发现一种非常常见的 USH2A 基因突变(39%)(c.11864G > A,p.(Trp3955*),可定义为“中欧东部等位基因”。关于 Alport 综合征,我们能够潜在地重新分类 COL4A3 基因中的致病性等位基因,该基因以前仅与良性家族性血尿相关。在所有其他情况下,基因组分析使我们能够确认已知致病基因的作用,并鉴定出几个新的和已知的等位基因。总的来说,我们的研究结果突出了将准确的临床特征与使用基因组技术(NGS 和 SNP 阵列)相结合对 SHL 进行分子诊断的有效性,这对所有患者的管理和治疗都有明显的积极影响。