Identification of Large Rearrangements of the PCDH15 Gene by Combined MLPA and a CGH: Large Duplications Are Responsible for Usher Syndrome
Identification of Large Rearrangements of the PCDH15 Gene by Combined MLPA and a CGH: Large Duplications Are Responsible for Usher Syndrome
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DOI：
10.1167/iovs.10-5359
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发表时间：
2010-11-01
影响因子：
4.4
通讯作者：
Millan, Jose M.
中科院分区：
文献类型：
--
作者：
Aller, Elena;Jaijo, Teresa;Millan, Jose M.
目的。编码原钙粘蛋白15的PCDH15在Usher综合征1F （USH1F）患者中发生突变。在该基因中不仅发现了点突变，而且还发现了大的缺失。然而，USH1F基因座的严重缺失的检测和表征一直很困难。本研究的目的是在一组患者中鉴定PCDH15的大基因组重排，并准确鉴定检测到的重排的连接断点的位置。使用PCDH15 MLPA（多重连接依赖探针扩增）商业试剂盒，结合定制的寡核苷酸阵列CGH分析（aCGH），包含近20,000个探针，覆盖PCDH15基因的非重复序列。在23例USH病例队列中的3个（13%）家族中发现了两个大的基因重排——一个缺失55kb，一个直接重复82kb。对这些患者进行了5种已知USH1基因的突变筛查，发现他们携带一种或不携带PCDH15的致病性突变。确定了两种重排的确切断点。这是首次发现大量重复基因与Usher综合征有关。尚未对USH患者进行大规模基因组重排（如重复和缺失）的广泛检测。这种类型的突变很容易逃脱传统pcr方法的检测。因此，结合基于pcr的突变筛选，以及缺失和重复分析，对于准确筛选Usher患者的PCDH15基因是必要的。（Invest Ophthalmol Vis Sci. 2010; 51: 5480-5485） DOI: 10.1167/iov .105359
PURPOSE. PCDH15, encoding protocadherin 15, is mutated in Usher syndrome type 1F (USH1F) patients. Not only point mutations, but also large deletions have been detected within this gene. However, the detection and characterization of gross deletions in the USH1F locus have been difficult. The purpose of the present work was to identify large genomic rearrangements of PCDH15 in a cohort of patients and to accurately identify the location of the junction breakpoints of the detected rearrangements.METHODS. A PCDH15 MLPA (multiplex ligation-dependent probe amplification) commercial kit was used, combined with a customized oligonucleotide array-based CGH analysis (aCGH), containing almost 20,000 probes tiling the nonrepetitive sequence of the PCDH15 gene.RESULTS. Two large intragenic rearrangements were identified-one deletion of 55 kb and one direct duplication of 82 kb-in 3 (13%) families from a cohort of 23 USH cases. The patients had been screened for mutations in the five known USH1 genes and were found to carry one or none of the pathogenic mutations in PCDH15. The exact breakpoints of both rearrangements were identified.CONCLUSIONS. This is the first time that large duplications have been associated with Usher syndrome. USH patients have not been extensively tested for large genomic rearrangements such as duplications and deletions. This type of mutation easily escapes detection by traditional PCR-based methods. Thus, a combination of PCR-based mutation screening, together with deletion and duplication analysis, is mandatory for the accurate screening of the PCDH15 gene in Usher patients. (Invest Ophthalmol Vis Sci. 2010; 51: 5480-5485) DOI: 10.1167/iovs.105359