The utility of massively parallel sequencing for posterior polymorphous corneal dystrophy type 3 molecular diagnosis. (May 2019)

• Record Type: Journal Article
• Authors: Dudakova, Lubica; Evans, Cerys J.; Pontikos, Nikolas; Hafford-Tear, Nathaniel J.; Malinka, Frantisek; Skalicka, Pavlina; Horinek, Ales; Munier, Francis L.; Voide, Nathalie; Studeny, Pavel; Vanikova, Lucia; Kubena, Tomas; Rojas Lopez, Karla E.; Davidson, Alice E.; Hardcastle, Alison J.; Tuft, Stephen J.; Liskova, Petra
• Is Part Of: Experimental eye research. Volume 182(2019)
• Page Start: 160
• Page End: 166
• Publication Date: 2019-05
• Subjects: ZEB1 -- Posterior polymorphous corneal dystrophy type 3 -- Massively parallel sequencing -- Exome -- Genome -- Aberrant splicing -- Breakpoint mapping; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2019.03.002
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: The aim of this study was to identify the molecular genetic cause of disease in posterior polymorphous corneal dystrophy (PPCD) probands of diverse origin and to assess the utility of massively parallel sequencing in the detection of ZEB1 mutations. We investigated a total of 12 families (five British, four Czech, one Slovak and two Swiss). Ten novel and two recurrent disease-causing mutations in ZEB1, were identified in probands by Sanger (n = 5), exome (n = 4) and genome (n = 3) sequencing. Sanger sequencing was used to confirm the mutations detected by massively parallel sequencing, and to perform segregation analysis. Genome sequencing revealed that one proband harboured a novel ∼0.34 Mb heterozygous de novo deletion spanning exons 1–7 and part of exon 8. Transcript analysis confirmed that the ZEB1 transcript is detectable in blood-derived RNA samples and that the disease-associated variant c.482-2A>G leads to aberrant pre-mRNA splicing. De novo mutations, which are a feature of PPCD3, were found in the current study with an incidence rate of at least 16.6%. In general, massively parallel sequencing is a time-efficient way to detect PPCD3-associated mutations and, importantly, genome sequencing enables the identification of full or partial heterozygous ZEB1 deletions that can evade detection by both Sanger and exome sequencing. These findings contribute to our understanding of PPCD3, for which currently, 49 pathogenic variants have been identified, all of which are predicted to be null alleles. Highlights: Whole genome sequencing is efficient for the detection of deletions in ZEB1. Variants affecting pre-mRNA splicing of ZEB1 can be studied in blood-derived cDNA. Ten novel ZEB1 mutations implicated in PPCD3 have been identified.