1. A novel CRX mutation by whole-exome sequencing in an autosomal dominant cone-rod dystrophy pedigree
- Author
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Qin-Kang Lu, Na Zhao, Ya-Su Lv, Wei-Kun Gong, Hui-Yun Wang, Qi-Hu Tong, Xiao-Ming Lai, Rong-Rong Liu, Ming-Yan Fang, Jian-Guo Zhang, Zhen-Fang Du, and Xian-Ning Zhang
- Subjects
cone-rod dystrophy ,autosomal dominant cone-rod dystrophy ,whole-exome sequencing ,Sanger sequencing ,CRX gene ,mutation ,Ophthalmology ,RE1-994 - Abstract
AIM: To identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD). METHODS: A southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-exome sequencing (WES), coupling the Agilent whole-exome capture system to the Illumina HiSeq 2000 DNA sequencing platform was used to search the specific gene mutation in 3 affected family members and 1 unaffected member. After a suggested variant was found through the data analysis, the putative mutation was validated by Sanger DNA sequencing of samples from all available family members. RESULTS: The results of both WES and Sanger sequencing revealed a novel nonsense mutation c.C766T (p.Q256X) within exon 5 of CRX gene which was pathogenic for adCORD in this family. The mutation could affect photoreceptor-specific gene expression with a dominant-negative effect and resulted in loss of the OTX tail, thus the mutant protein occupies the CRX-binding site in target promoters without establishing an interaction and, consequently, may block transactivation. CONCLUSION: All modes of Mendelian inheritance in CORD have been observed, and genetic heterogeneity is a hallmark of CORD. Therefore, conventional genetic diagnosis of CORD would be time-consuming and labor-intensive. Our study indicated the robustness and cost-effectiveness of WES in the genetic diagnosis of CORD.
- Published
- 2015
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