Abstract
Abstract: :
Purpose: Coats' type retinitis pigmentosa was first described as a distinct entity by an Italian ophthalmologist Zamorani in 1956. Since then, only handful reports have appeared in the literature. The human homologue of Drosophila crumbs gene (CRB1) has been associated with some cases of Coats' type RP. CRB1 is preferentially expressed in the retina, but its function is largely unknown. We have identified 2 patients with Coats' type RP. Current study is designed to characterize the clinical features and to screen for mutations in CRB1 gene in these 2 patients. Methods: 1) Complete ophthalmic examinations and color fundus photos, electroretinogram (ERG), visual field (VF) and fluorescein angiography (FA) were performed. 2) Peripheral blood was obtained, and DNA was extracted. 3) Primers were designed to amplify each exon of the entire CRB1 gene. Direct sequencing will be conducted to screen for mutations. Results: We have identified 2 patients with Coats' type RP. Neither of these 2 patients has positive family history or parental consanguinity. Both have symptoms of nyctalopia, constriction of visual field and decreased central vision. One of the patient is mild hyperopic with mild astigmatism. They both have posterior subcapsular cataract and positive vitreous cells. Fundus exam and FA on both patients revealed typical RP features with Coats' type changes in the bilateral infrotemporal quadrants. One patient has bilateral bull's eye maculopathy. ERG of the both patients was extinguished and VF was constricted. The mutational screening using direct sequencing methods is in progress. Conclusion: We have clinically characterized two Coats' type RP patients and conducted genetic studies. A better understanding of clinical features and genetic etiology of Coats' type RP will aid improved diagnosis and development of new therapies. Cole Eye Institute, NIH, Steinbach Fund.
Keywords: 562 retinal degenerations: hereditary • 335 candidate gene analysis