A novel Cx50 (GJA8) p.H277Y mutation associated with autosomal dominant congenital cataract identified with targeted next-generation sequencing
A novel Cx50 (GJA8) p.H277Y mutation associated with autosomal dominant congenital cataract identified with targeted next-generation sequencing
复制标题
通过靶向下一代测序鉴定出与常染色体显性先天性白内障相关的新型 Cx50 (GJA8) p.H277Y 突变
DOI：
10.1007/s00417-015-3019-x
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发表时间：
2015-06-01
影响因子：
2.7
通讯作者：
Xu, Xun
中科院分区：
文献类型：
--
作者：
Chen, Chong;Sun, Qiao;Xu, Xun
为揭示中国四代家庭常染色体显性先天性粉状核性白内障的分子遗传背景，收集家族史资料，进行眼科检查，并从家庭成员的外周血中提取基因组DNA。通过靶向二代测序捕获候选基因并测序，并通过桑格测序证实结果。基于Swiss-Model Server对蛋白质进行结构建模，并利用Antheprot 2000软件预测其二级结构可能发生的变化。使用 Grantham 评分、PolyPhen-2 和 SIFT 预测来评估氨基酸取代的化学差异和可能的功能影响。通过共聚焦显微镜评估蛋白质分布。鉴定出一种新型杂合性 c.829C > T 转变，该转变导致 connexin50 (Cx50、GJA8) 编码区中密码子 277 (p.H277Y) 处的高度保守的组氨酸被酪氨酸取代。生物信息学分析表明，该突变可能通过用转角替换COOH末端部分的螺旋来改变蛋白质的二级结构。根据 Grantham 评分，该突变被预测为中度保守，而 PolyPhen-2 和 SIFT 均预测该突变为有害，结果一致。此外，当在COS1细胞中表达时，该突变导致蛋白质积累并引起Cx 50蛋白质定位模式的变化。这是在Cx50的外显子2中鉴定的新型错义突变[c.829C > T，(p.H277Y)]。我们的研究结果扩大了与常染色体显性先天性粉状核性白内障相关的 Cx50 突变谱。
To unravel the molecular genetic background responsible for autosomal dominant congenital pulverulent nuclear cataracts in a four-generation Chinese family.Family history data were collected, ophthalmological examinations were performed, and genomic DNA was extracted from peripheral blood of the family members. The candidate genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The structure modelling of the protein was displayed based on Swiss-Model Server, and its possible changes in the secondary structure were predicted using Antheprot 2000 software. The chemical dissimilarity and possible functional impact of an amino acid substitution were performed with Grantham score, PolyPhen-2, and SIFT predictions. Protein distributions were assessed by confocal microscopy.A novel heterozygous c.829C > T transition that led to the substitution of a highly conserved histidine by tyrosine at codon 277 (p.H277Y) in the coding region of connexin50 (Cx50, GJA8) was identified. Bioinformatics analysis showed that the mutation likely altered the secondary structure of the protein by replacing the helix of the COOH-terminal portion with a turn. The mutation was predicted to be moderately conservative by Grantham score and to be deleterious by both PolyPhen-2 and SIFT with consistent results. In addition, when expressed in COS1 cells, the mutation led to protein accumulation and caused changes in Cx 50 protein localization pattern.This is a novel missense mutation [c.829C > T, (p.H277Y)] identified in exon 2 of Cx50. Our findings expand the spectrum of Cx50 mutations that are associated with autosomal dominant congenital pulverulent nuclear cataract.