PURPOSE: To review three inherited retinal disorders associated with diagnostic or pathognomonic electroretinogram (ERG) abnormalities: cone dystrophy with supernormal rod ERG (KCNV2), enhanced S-cone syndrome (NR2E3), and bradyopsia (RGS9/R9AP). METHODS: A review of clinical details, genetic basis, and electrophysiological features in these disorders and a brief summary of the standard and nonstandard ERG techniques required to identify the disorders. RESULTS: The electrophysiological features in each of these three disorders are pathognomonic such that the responsible gene can be specified. The results from nonstandard electrophysiological testing in excess of international standards are necessary to describe the pathognomonic changes in cone dystrophy with supernormal rod ERG and bradyopsia. The clinical phenotype in the disorders can be variable. Mutations in NR2E3 may additionally be associated with phenotypes other than enhanced S-cone syndrome. CONCLUSION: : Characteristic ERG changes enable the diagnosis of cone dystrophy with supernormal rod ERG, enhanced S-cone syndrome, and bradyopsia and accurate genetic screening. This review highlights the need for additional nonstandard ERGs to make the diagnosis in two of these disorders.
PURPOSE: To review three inherited retinal disorders associated with diagnostic or pathognomonic electroretinogram (ERG) abnormalities: cone dystrophy with supernormal rod ERG (KCNV2), enhanced S-cone syndrome (NR2E3), and bradyopsia (RGS9/R9AP). METHODS: A review of clinical details, genetic basis, and electrophysiological features in these disorders and a brief summary of the standard and nonstandard ERG techniques required to identify the disorders. RESULTS: The electrophysiological features in each of these three disorders are pathognomonic such that the responsible gene can be specified. The results from nonstandard electrophysiological testing in excess of international standards are necessary to describe the pathognomonic changes in cone dystrophy with supernormal rod ERG and bradyopsia. The clinical phenotype in the disorders can be variable. Mutations in NR2E3 may additionally be associated with phenotypes other than enhanced S-cone syndrome. CONCLUSION: : Characteristic ERG changes enable the diagnosis of cone dystrophy with supernormal rod ERG, enhanced S-cone syndrome, and bradyopsia and accurate genetic screening. This review highlights the need for additional nonstandard ERGs to make the diagnosis in two of these disorders.
Authors: Frederick T Collison; Jason C Park; Gerald A Fishman; Edwin M Stone; J Jason McAnany Journal: Doc Ophthalmol Date: 2016-03-31 Impact factor: 2.379
Authors: Michalis Georgiou; Anthony G Robson; Kaoru Fujinami; Shaun M Leo; Ajoy Vincent; Fadi Nasser; Thales Antônio Cabral De Guimarães; Samer Khateb; Nikolas Pontikos; Yu Fujinami-Yokokawa; Xiao Liu; Kazushige Tsunoda; Takaaki Hayashi; Mauricio E Vargas; Alberta A H J Thiadens; Emanuel R de Carvalho; Xuan-Thanh-An Nguyen; Gavin Arno; Omar A Mahroo; Maria Inmaculada Martin-Merida; Belen Jimenez-Rolando; Gema Gordo; Ester Carreño; Ayuso Carmen; Dror Sharon; Susanne Kohl; Rachel M Huckfeldt; Bernd Wissinger; Camiel J F Boon; Eyal Banin; Mark E Pennesi; Arif O Khan; Andrew R Webster; Eberhart Zrenner; Elise Héon; Michel Michaelides Journal: Am J Ophthalmol Date: 2020-12-11 Impact factor: 5.258