Genotype-Phenotype Correlation for TGFBI Corneal Dystrophies Identifies p.(G623D) as a Novel Cause of Epithelial Basement Membrane Dystrophy
Autor: | Caroline Thaung, Alice E. Davidson, Stephen J. Tuft, Cerys J. Evans, Alison J. Hardcastle, Neyme Veli, Karla E. Rojas Lopez, Nicole Carnt |
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Rok vydání: | 2016 |
Předmět: |
0301 basic medicine
Proband Adult Male Pathology medicine.medical_specialty Genotype DNA Mutational Analysis Microscopy Acoustic Corneal dystrophy Biology Basement Membrane Cornea Transforming Growth Factor beta1 03 medical and health sciences 0302 clinical medicine Genotype-phenotype distinction medicine Humans Genetic Association Studies Corneal Dystrophies Hereditary Dystrophy DNA Exons medicine.disease eye diseases Pedigree Epithelial basement membrane dystrophy 030104 developmental biology Phenotype Mutation 030221 ophthalmology & optometry Lattice corneal dystrophy Female TGFBI |
Zdroj: | Investigative ophthalmologyvisual science. 57(13) |
ISSN: | 1552-5783 |
Popis: | Purpose: The majority of anterior corneal dystrophies are caused by dominant mutations in TGFBI (transforming growth factor β-induced) collectively known as the epithelial-stromal TGFBI dystrophies. Most cases of epithelial basement membrane dystrophy (EBMD) are thought to result from a degenerative (nongenetic) process; however, a minority of cases are associated with specific TGFBI mutations. We evaluated the spectrum of TGFBI mutations and associated phenotypes in a United Kingdom cohort with typical epithelial-stromal TGFBI dystrophies and an EBMD cohort. Methods: We recruited 68 probands with a clinical diagnosis of epithelial-stromal TGFBI dystrophy and 23 probands with bilateral EBMD. DNA was extracted from peripheral leukocytes, and TGFBI was bi-directly Sanger sequenced. Results: Nine TGFBI mutations were identified. The most common occurred at the mutation hot-spot residues R124 and R555 in 61 probands; these individuals had a genotype-phenotype correlation consistent with prior reports. Four probands with lattice corneal dystrophy carried a mutation in exon 14: p.(A620D), p.(V625D), and p.(H626R). We identified a p.(G623D) mutation in five probands, including two probands from the EBMD cohort. These subjects typically had an onset of severe recurrent corneal epithelial erosion in the fourth decade with mild diffuse or geographic subepithelial corneal opacities and only small anterior stromal lattice structures in older individuals. Symptoms of painful epithelial erosion improved markedly following phototherapeutic keratectomy. Conclusions: There was a strong correlation between genotype and phenotype for the majority of TGFBI mutations. In this cohort, the p.(G623D) mutation caused a greater proportion of TGFBI-associated disease than anticipated, associated with variable phenotypes including individuals diagnosed with EBMD. |
Databáze: | OpenAIRE |
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