* Department of Audiology, The Sahlgrenska Academy, Institute of Neuroscience and Physiology , Göteborg , Sweden.
Int J Audiol. 2013 Dec;52(12):832-7. doi: 10.3109/14992027.2013.839885. Epub 2013 Oct 28.
The purpose of this study was to compare the genotype/phenotype relationship between siblings with identical USH2A pathologic mutations and the consequent audiologic phenotypes, in particular degree of hearing loss (HL). Decade audiograms were also compared among two groups of affected subjects with different mutations of USH2A.
DNA samples from patients with Usher syndrome type II were analysed. The audiological features of patients and affected siblings with USH2A mutations were also examined to identify genotype-phenotype correlations.
Genetic and audiometric examinations were performed in 18 subjects from nine families with Usher syndrome type IIA.
Three different USH2A mutations were identified in the affected subjects. Both similarities and differences of the auditory phenotype were seen in families with several affected siblings. A variable degree of hearing loss, ranging from mild to profound, was observed among affected subjects. No significant differences in hearing thresholds were found the group of affected subjects with different pathological mutations.
Our results indicate that mutations in the USH2A gene and the resulting phenotype are probably modulated by other variables, such as modifying genes, epigenetics or environmental factors which may be of importance for better understanding the etiology of Usher syndrome.
本研究旨在比较具有相同 USH2A 病理突变的同卵双胞胎之间的基因型/表型关系及其随后的听力学表型，特别是听力损失（HL）程度。还比较了两组具有不同 USH2A 突变的受影响受试者的十年听力图。
分析了 II 型 Usher 综合征患者的 DNA 样本。还检查了 USH2A 突变患者和受影响兄弟姐妹的听力学特征，以确定基因型-表型相关性。
对 9 个 IIA 型 Usher 综合征家族的 18 名受影响受试者进行了遗传和听力检查。
在受影响的受试者中发现了三种不同的 USH2A 突变。具有多个受影响兄弟姐妹的家庭中出现了听觉表型的相似和差异。受影响受试者的听力损失程度从轻度到重度不等。具有不同病理突变的受影响受试者组的听力阈值无显著差异。
我们的结果表明，USH2A 基因的突变和由此产生的表型可能受到其他变量的调节，例如修饰基因、表观遗传学或环境因素，这些因素对于更好地理解 Usher 综合征的病因可能很重要。
