Alice E Davidson1, Edmondo Borasio2, Petra Liskova3, Arif O Khan4, Hala Hassan5, Michael E Cheetham1, Vincent Plagnol6, Fowzan S Alkuraya4, Stephen J Tuft7, Alison J Hardcastle1. 1. UCL Institute of Ophthalmology, London, United Kingdom. 2. Moorfields Eye Hospital, Al Razi Building, Dubai Healthcare City, Dubai, United Arab Emirates. 3. Moorfields Eye Hospital, London, United Kingdom Institute of Inherited Metabolic Diseases and First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic. 4. Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. 5. Moorfields Eye Hospital, London, United Kingdom. 6. UCL Genetics Institute, London, United Kingdom. 7. UCL Institute of Ophthalmology, London, United Kingdom Moorfields Eye Hospital, London, United Kingdom.
Abstract
PURPOSE: Brittle cornea syndrome 1 (BCS1) is a rare recessive condition characterized by extreme thinning of the cornea and sclera, caused by mutations in ZNF469. Keratoconus is a relatively common disease characterized by progressive thinning and ectasia of the cornea. The etiology of keratoconus is complex and not yet understood, but rare ZNF469 variants have recently been associated with disease. We investigated the phenotype of BCS1 carriers with known pathogenic ZNF469 mutations, and recruited families in which aggregation of keratoconus was observed to establish if rare variants in ZNF469 segregated with disease. METHODS: Patients and family members were recruited and underwent comprehensive anterior segment examination, including corneal topography. Blood samples were donated and genomic DNA was extracted. The coding sequence and splice sites of ZNF469 were PCR amplified and Sanger sequenced. RESULTS: Four carriers of three BCS1-associated ZNF469 loss-of-function mutations (p.[Glu1392Ter], p.[Gln1930Argfs*6], p.[Gln1930fs*133]) were examined and none had keratoconus. One carrier had partially penetrant features of BCS1, including joint hypermobility. ZNF469 sequencing in 11 keratoconus families identified 9 rare (minor allele frequency [MAF] ≤ 0.025) variants predicted to be potentially damaging. However, in each instance the rare variant(s) identified, including two previously reported as potentially keratoconus-associated, did not segregate with the disease. CONCLUSIONS: The presence of heterozygous loss-of-function alleles in the ZNF469 gene did not cause keratoconus in the individuals examined. None of the rare nonsynonymous ZNF469 variants identified in the familial cohort conferred a high risk of keratoconus; therefore, genetic variants contributing to disease pathogenesis in these 11 families remain to be identified. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE:Brittle cornea syndrome 1 (BCS1) is a rare recessive condition characterized by extreme thinning of the cornea and sclera, caused by mutations in ZNF469. Keratoconus is a relatively common disease characterized by progressive thinning and ectasia of the cornea. The etiology of keratoconus is complex and not yet understood, but rare ZNF469 variants have recently been associated with disease. We investigated the phenotype of BCS1 carriers with known pathogenic ZNF469 mutations, and recruited families in which aggregation of keratoconus was observed to establish if rare variants in ZNF469 segregated with disease. METHODS:Patients and family members were recruited and underwent comprehensive anterior segment examination, including corneal topography. Blood samples were donated and genomic DNA was extracted. The coding sequence and splice sites of ZNF469 were PCR amplified and Sanger sequenced. RESULTS: Four carriers of three BCS1-associated ZNF469 loss-of-function mutations (p.[Glu1392Ter], p.[Gln1930Argfs*6], p.[Gln1930fs*133]) were examined and none had keratoconus. One carrier had partially penetrant features of BCS1, including joint hypermobility. ZNF469 sequencing in 11 keratoconus families identified 9 rare (minor allele frequency [MAF] ≤ 0.025) variants predicted to be potentially damaging. However, in each instance the rare variant(s) identified, including two previously reported as potentially keratoconus-associated, did not segregate with the disease. CONCLUSIONS: The presence of heterozygous loss-of-function alleles in the ZNF469 gene did not cause keratoconus in the individuals examined. None of the rare nonsynonymous ZNF469 variants identified in the familial cohort conferred a high risk of keratoconus; therefore, genetic variants contributing to disease pathogenesis in these 11 families remain to be identified. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Rocío Arce-González; Oscar Francisco Chacon-Camacho; Vianey Ordoñez-Labastida; Enrique O Graue-Hernandez; Alejandro Navas-Pérez; Juan Carlos Zenteno Journal: Int Ophthalmol Date: 2022-09-01 Impact factor: 2.029
Authors: Georgia Avgitidou; Sebastian Siebelmann; Bjoern Bachmann; Juergen Kohlhase; Ludwig M Heindl; Claus Cursiefen Journal: Case Rep Ophthalmol Med Date: 2015-06-29