title: A COL17A1 Splice-Altering Mutation Is Prevalent in Inherited Recurrent Corneal Erosions.
abstract: OBJECTIVE
  Corneal dystrophies are a genetically heterogeneous group of disorders. We previously described a family with an autosomal dominant epithelial recurrent erosion dystrophy (ERED). We aimed to identify the underlying genetic cause of ERED in this family and 3 additional ERED families. We sought to characterize the potential function of the candidate genes using the human and zebrafish cornea.
  
  
  METHODS
  Case series study of 4 white families with a similar ERED. An experimental study was performed on human and zebrafish tissue to examine the putative biological function of candidate genes.
  
  
  METHODS
  Four ERED families, including 28 affected and 17 unaffected individuals.
  
  
  METHODS
  HumanLinkage-12 arrays (Illumina, San Diego, CA) were used to genotype 17 family members. Next-generation exome sequencing was performed on an uncle-niece pair. Segregation of potential causative mutations was confirmed using Sanger sequencing. Protein expression was determined using immunohistochemistry in human and zebrafish cornea. Gene expression in zebrafish was assessed using whole-mount in situ hybridization. Morpholino-induced transient gene knockdown was performed in zebrafish embryos.
  
  
  METHODS
  Linkage microarray, exome analysis, DNA sequence analysis, immunohistochemistry, in situ hybridization, and morpholino-induced genetic knockdown results.
  
  
  RESULTS
  Linkage microarray analysis identified a candidate region on chromosome chr10:12,576,562-112,763,135, and exploration of exome sequencing data identified 8 putative pathogenic variants in this linkage region. Two variants segregated in 06NZ-TRB1 with ERED: COL17A1 c.3156C→T and DNAJC9 c.334G→A. The COL17A1 c.3156C→T variant segregated in all 4 ERED families. We showed biologically relevant expression of these proteins in human cornea. Both proteins are expressed in the cornea of zebrafish embryos and adults. Zebrafish lacking Col17a1a and Dnajc9 during development show no gross corneal phenotype.
  
  
  CONCLUSIONS
  The COL17A1 c.3156C→T variant is the likely causative mutation in our recurrent corneal erosion families, and its presence in 4 independent families suggests that it is prevalent in ERED. This same COL17A1 c.3156C→T variant recently was identified in a separate pedigree with ERED. Our study expands the phenotypic spectrum of COL17A1 disease from autosomal recessive epidermolysis bullosa to autosomal dominant ERED and identifies COL17A1 as a key protein in maintaining integrity of the corneal epithelium.
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Verity F
authors.initials: VF
authors.lastname: Oliver
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: van Bysterveldt
authors.affiliation: Department of Biochemistry, Dunedin School of Medicine, Otago University, Dunedin, New Zealand.
authors.forename: Murray
authors.initials: M
authors.lastname: Cadzow
authors.affiliation: Department of Corneal and External Eye Diseases, St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Steger
authors.affiliation: Department of Corneal and External Eye Diseases, St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom.
authors.forename: Vito
authors.initials: V
authors.lastname: Romano
authors.affiliation: Pathology Department, Dunedin School of Medicine, Otago University, Dunedin, New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Markie
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia; Lions Eye Institute, University of Western Australia, Perth, Australia.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia; Lions Eye Institute, University of Western Australia, Perth, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
authors.affiliation: Department of Corneal and External Eye Diseases, St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom; Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Colin E
authors.initials: CE
authors.lastname: Willoughby
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Trevor
authors.initials: T
authors.lastname: Sherwin
authors.affiliation: Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Crosier
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand; Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand.
authors.forename: Charles N
authors.initials: CN
authors.lastname: McGhee
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand; Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand. Electronic address: a.vincent@auckland.ac.nz.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Vincent
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001324:Autoantigens / Q000235:genetics*; D002648:Child; D003317:Corneal Dystrophies, Hereditary / Q000175:diagnosis / Q000235:genetics*; D004195:Disease Models, Animal; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D020868:Gene Silencing; D008040:Genetic Linkage; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D018895:Microsatellite Repeats; D018613:Microscopy, Confocal; D008875:Middle Aged; D009154:Mutation; D024041:Non-Fibrillar Collagens / Q000235:genetics*; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015027:Zebrafish; D000097805:Collagen Type XVII
chemical_list: D001324:Autoantigens; D050956:HSP40 Heat-Shock Proteins; D024041:Non-Fibrillar Collagens; D000097805:Collagen Type XVII; C494654:DNAJC9 protein, human