Heterozygous deletions at the ZEB1 locus verify haploinsufficiency as the mechanism of disease for posterior polymorphous corneal dystrophy type 3
Heterozygous deletions at the ZEB1 locus verify haploinsufficiency as the mechanism of disease for posterior polymorphous corneal dystrophy type 3
复制标题
DOI：
10.1038/ejhg.2015.232
复制
发表时间：
2016-07-01
影响因子：
5.2
通讯作者：
Hardcastle, Alison J.
中科院分区：
文献类型：
--
作者：
Liskova, Petra;Evans, Cerys J.;Hardcastle, Alison J.
相当一部分患有后部多形性角膜营养不良（PPCD）的患者缺乏分子诊断。我们评估了14个不相关的先证者，他们有PPCD的临床诊断，以前通过直接测序确定ZEB1突变为阴性。使用了一系列技术，包括全外显子组测序（WES），单核苷酸多态性（SNP）阵列拷贝数变异（CNV）分析，定量实时PCR和远程PCR。在可能的情况下，在家庭成员中确认了潜在致病性变化与疾病的分离。WES在一个三代PPCD家族中鉴定了10号染色体上的一个假定纯合性运行，提示杂合性缺失。SNP阵列基因分型，然后进行长程PCR和直接测序以确定断点，证实了包含多个基因（包括ZEB 1）的大缺失的存在。一个跨越ZEB1的杂合缺失的鉴定促使我们进一步研究在其余先证者中该位点的潜在CNV，导致检测到另外两个杂合ZEB1基因缺失。这项研究表明，ZEB1突变占PPCD的比例比以前估计的更大，并支持ZEB1单倍不足是PPCD 3疾病的潜在分子机制的假设。
A substantial proportion of patients with posterior polymorphous corneal dystrophy (PPCD) lack a molecular diagnosis. We evaluated 14 unrelated probands who had a clinical diagnosis of PPCD who were previously determined to be negative for mutations in ZEB1 by direct sequencing. A combination of techniques was used including whole-exome sequencing (WES), single-nucleotide polymorphism (SNP) array copy number variation (CNV) analysis, quantitative real-time PCR, and long-range PCR. Segregation of potentially pathogenic changes with disease was confirmed, where possible, in family members. A putative run of homozygosity on chromosome 10 was identified by WES in a three-generation PPCD family, suggestive of a heterozygous deletion. SNP array genotyping followed by long-range PCR and direct sequencing to define the breakpoints confirmed the presence of a large deletion that encompassed multiple genes, including ZEB1. Identification of a heterozygous deletion spanning ZEB1 prompted us to further investigate potential CNVs at this locus in the remaining probands, leading to detection of two additional heterozygous ZEB1 gene deletions. This study demonstrates that ZEB1 mutations account for a larger proportion of PPCD than previously estimated, and supports the hypothesis that haploinsufficiency of ZEB1 is the underlying molecular mechanism of disease for PPCD3.