Bakhtiari Pejman, Frausto Ricardo F, Roldan Ashley N, Wang Cynthia, Yu Fei, Aldave Anthony J
The Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7003, USA.
Mol Vis. 2013;19:575-80. Epub 2013 Mar 15.
To report the identification of five novel nonsense mutations in the zinc finger E-box binding homeobox 1 (ZEB1) gene and exclusion of promoter region mutations in individuals without ZEB1 coding region mutations in posterior polymorphous corneal dystrophy (PPCD).
Slit-lamp examination and DNA collection were performed for individuals diagnosed with PPCD and, when available, affected and unaffected family members. Genomic DNA prepared from peripheral blood leukocytes and buccal epithelial cells underwent PCR amplification and automated sequencing of the ZEB1 gene and 1 kb 5' of ZEB1, presumably containing the ZEB1 promoter region.
Thirteen unrelated individuals with PPCD were identified, and genomic DNA was collected from each individual. ZEB1 mutations were identified in six of the 13 probands, five of which were novel: p.(Gly150Alafs36; spontaneous), p.(His230Argfs7), p.(Ser638Cysfs5), p.(Glu1039Glyfs6), and p.(Gln884Argfs*37). Screening of the ZEB1 promoter region in 31 probands with PPCD without a ZEB1 coding region mutation identified only two known single nucleotide polymorphisms (SNPs) whose frequency in the affected probands did not differ significantly from that in the general population.
We report five novel frame-shift mutations, one confirmed as spontaneous, in the ZEB1 gene associated with PPCD, bringing the total number of reported pathogenic mutations to 24, and the percentage of PPCD associated with ZEB1 mutations to 32%. The absence of ZEB1 promoter region mutations in probands without a ZEB1 coding region mutation indicates that other genetic loci, such as the PPCD1 locus, are involved in the pathogenesis of PPCD.
报告在锌指E盒结合同源框1(ZEB1)基因中鉴定出的5个新的无义突变,并排除后部多形性角膜营养不良(PPCD)中无ZEB1编码区突变个体的启动子区域突变。
对诊断为PPCD的个体以及可获得的受累和未受累家庭成员进行裂隙灯检查和DNA采集。从外周血白细胞和颊上皮细胞制备的基因组DNA进行PCR扩增,并对ZEB1基因及其5'端1 kb区域(推测包含ZEB1启动子区域)进行自动测序。
鉴定出13例无亲缘关系的PPCD个体,并从每个个体收集了基因组DNA。在13名先证者中的6名中鉴定出ZEB1突变,其中5个是新的:p.(Gly150Alafs36;自发)、p.(His230Argfs7)、p.(Ser638Cysfs5)、p.(Glu1039Glyfs6)和p.(Gln884Argfs*37)。对31例无ZEB1编码区突变的PPCD先证者的ZEB1启动子区域进行筛查,仅发现两个已知的单核苷酸多态性(SNP),其在受累先证者中的频率与一般人群中的频率无显著差异。
我们报告了与PPCD相关的ZEB1基因中的5个新的移码突变,其中1个确认为自发突变,使报告的致病突变总数达到24个,与ZEB1突变相关的PPCD比例达到32%。在无ZEB1编码区突变的先证者中未发现ZEB1启动子区域突变,这表明其他基因位点,如PPCD1位点,参与了PPCD的发病机制。