Experimental assessment of novel PAX6 splicing mutations in two Chinese families with aniridia
Experimental assessment of novel PAX6 splicing mutations in two Chinese families with aniridia
复制标题
两个中国无虹膜家系中新型 PAX6 剪接突变的实验评估
DOI：
10.1016/j.gene.2017.07.073
复制
发表时间：
2017-09-30
期刊：
影响因子：
3.5
通讯作者：
Shentu, Xingchao
中科院分区：
文献类型：
--
作者：
Miao, Qi;Ping, Xiyuan;Shentu, Xingchao
无虹膜是一种罕见的先天性眼部疾病，由配对盒基因6（PAX 6）（OMIM 607108）突变引起，该基因编码一种高度保守的转录调节因子。为了研究两个无虹膜家系的临床特征和遗传缺陷，我们招募了该家系成员和200名种族匹配的对照。分析了PAX 6基因（NG_008679.1）的整个外显子和侧翼内含子序列，并使用pET 01的外显子捕获试验在硅胶和体外评估了变体对剪接的影响。在家族1中鉴定的供体位点（c.1183 + 1G > A）突变将导致外显子12的完全跳跃，并引起移码和超过正常终止密码子的连续翻译，产生具有延伸的COOH末端结构域的扩大的PAX 6蛋白。在家族2中检测到新的c.1033-1_1033delinsCT突变。该突变引起外显子12的完全跳跃和缺失7 bp的外显子12的部分跳跃。这将导致移码翻译和引入早熟终止密码，这导致可能被降解的严重截短的PAX 6蛋白。我们的研究进一步扩展了PAX 6的遗传病理学谱。
Aniridia is a rare, congenital ocular disorder caused by the mutations of the paired box gene-6 (PAX6) (OMIM 607108), which encodes a highly conserved transcriptional regulator. In order to investigate the clinical characterizations and genetic defects of two Chinese families affected with aniridia, we recruited the family members and 200 ethnically matched controls. The entire exons and flanking intronic sequences of the PAX6 gene (NG_008679.1) were analyzed and effects of variants on splicing were assessed in silica and in vitro using exon trapping assay with pET01. The donor site (c.1183 + 1G > A) mutation identified in family 1 would result in a complete skipping of exon 12 and cause a frameshift and run-on translation past the normal termination codon, creating an enlarged PAX6 protein with extended COOH-terminal domain. Novel c.1033-1_1033delinsCT mutation was detected in family 2. This mutation provoked both complete exon 12 skipping and partial skipping of exon 12 deleting 7 bp. This would lead to a frameshift translation and the introduction of pre-mature termination code, which resulted in severely truncated PAX6 protein likely to be degraded. Our study further expands the spectrum of genetic pathology underlying PAX6.