Choi Byung Yoon, Stewart Andrew K, Nishimura Katherine K, Cha Won Jae, Seong Moon-Woo, Park Sung Sup, Kim Seung Won, Chun Yang Sook, Chung Jong Woo, Park Shi-Nae, Chang Sun O, Kim Chong-Sun, Alper Seth L, Griffith Andrew J, Oh Seung-Ha
Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
Genet Test Mol Biomarkers. 2009 Oct;13(5):679-87. doi: 10.1089/gtmb.2009.0054.
Enlargement of the vestibular aqueduct (EVA) is a commonly detected inner ear anomaly related to hearing loss and often associated with mutations of SLC26A4 encoding pendrin, a transmembrane exchanger of Cl(-), I(-), and HCO(3)(-). Here we describe the phenotypes of 27 Korean EVA subjects and their SLC26A4 genotypes determined by bidirectional nucleotide sequencing.
The detected variants include two novel missense substitutions (p.V138L and p.P542R). We characterized the ability of p.V138L and p.P542R pendrin products to traffic to the plasma membrane in COS-7 cells and to transport Cl(-), I(-), and HCO(3)(-) in Xenopus oocytes. The results indicate that p.P542R is a benign polymorphic variant, whereas p.V138L is a pathogenic mutation. Since this and other studies of East Asian EVA cohorts show that the majority of SLC26A4 mutations affect either or both of two amplicons (exons 7-8 and 19), we developed a hierarchical protocol that integrates direct sequencing with denaturing high-performance liquid chromatography analyses for detection of SLC26A4 mutations in these populations. We validated the cost efficiency of the integrated protocol by a simulated screen of published East Asian EVA cohorts with known SLC26A4 genotypes.
Our study further defines the spectrum of SLC26A4 mutations among East Asians and demonstrates a rapid and efficient protocol for their detection.
前庭导水管扩大（EVA）是一种常见的内耳异常，与听力损失有关，且常与编码pendrin（一种Cl(-)、I(-)和HCO(3)(-)的跨膜交换器）的SLC26A4基因突变相关。在此，我们描述了27名韩国EVA患者的表型及其通过双向核苷酸测序确定的SLC26A4基因型。
检测到的变异包括两个新的错义替换（p.V138L和p.P542R）。我们对p.V138L和p.P542R pendrin产物在COS-7细胞中转运至质膜的能力以及在非洲爪蟾卵母细胞中转运Cl(-)、I(-)和HCO(3)(-)的能力进行了表征。结果表明，p.P542R是一种良性多态性变异，而p.V138L是一种致病突变。由于本研究以及其他针对东亚EVA队列的研究表明，大多数SLC26A4突变影响两个扩增子（外显子7 - 8和19）中的一个或两个，我们开发了一种分级方案，将直接测序与变性高效液相色谱分析相结合，用于检测这些人群中的SLC26A4突变。我们通过对已知SLC26A4基因型的已发表东亚EVA队列进行模拟筛查，验证了该综合方案的成本效益。
我们的研究进一步明确了东亚人群中SLC26A4突变的谱，并展示了一种快速有效的检测方案。
