Abstract
Abstract: :
Purpose:Though age-related macular degeneration (AMD) is the leading cause of irreversible central visual loss in the developed world, little is known about the etiology of this disorder. We report a large family with an autosomal dominant form of AMD and describe our genetic linkage study to map the disease-causing gene. Methods:Clinical features were determined by visual acuity measurement and ophthalmoscopic examination. Fundus photos and fluorescein angiograms were obtained for two affected individuals. Blood samples were obtained and genetic linkage studies were performed in all members of the cohort using a candidate-loci directed genome scan employing short tandem repeat polymorphic DNA markers. Results:Of 26 individuals at risk for AMD 14 were found, by ophthalmic examination, to manifest macular changes consistent with various stages of the disorder. Findings included large soft drusen in the macula in 7 patients, RPE pigmentary changes in 2 patients, geographic atrophy in 4 patients, and choroidal neovascularization in the remaining one affected patient. No significant linkage was found to any of the loci for AMD or several early-onset macular dystrophies investigated, including ARMD1, ABCA4, ELOVL4, STGD4, EFEMP1, or TIM-3. Conclusion:We have identified a new family with dominantly inherited AMD. The putative disease-causing gene did not map to any previously reported loci for AMD or any other macular dystrophies. A genome-wide search for this gene is in progress. This study will provide insight into pathogenesis of AMD, aid in the identification of at-risk patients and contribute to the development of potential therapies for this disorder.
Keywords: 308 age-related macular degeneration • 420 genetics • 418 gene mapping