Ramon A C van Huet1, Rob W J Collin2, Anna M Siemiatkowska2, Caroline C W Klaver3, Carel B Hoyng1, Francesca Simonelli4, Muhammad I Khan5, Raheel Qamar6, Eyal Banin7, Frans P M Cremers2, Thomas Theelen1, Anneke I den Hollander1, L Ingeborgh van den Born8, B Jeroen Klevering1. 1. Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands. 2. Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands. 3. Erasmus University Rotterdam Medical Center, Rotterdam, The Netherlands. 4. Department of Ophthalmology, Seconda Università degli Studi di Napoli, Naples, Italy. 5. Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan. 6. Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan Shifa College of Medicine, Islamabad, Pakistan. 7. Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. 8. The Rotterdam Eye Hospital, Rotterdam, The Netherlands.
Abstract
PURPOSE: To provide the first detailed clinical description in patients with RP caused by recessive mutations in IMPG2. METHODS: This international collaborative study includes 17 RP patients with inherited retinal disease caused by mutations in IMPG2. The patients were clinically (re-)examined, including extensive medical history taking, slit-lamp biomicroscopy, ophthalmoscopy, perimetry, ERG, optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, fundus photography, and color vision tests. The main outcome measures included mean age at onset, initial symptom, best-corrected visual acuity, fundus appearance, perimetry results, ERG responses, OCT images, FAF imaging, color vision test reports and DNA sequence variants. RESULTS: The mean age at onset was 10.5 years (range, 4-20 years). Initial symptoms included night blindness in 59% of patients, a decreased visual acuity in 35%, and visual field loss in 6%. Fundus abnormalities were typical of RP: optic disc pallor, attenuated vessels, bone spicules, and generalized atrophy of the retina and choriocapillaris. Additionally, we observed macular abnormalities in all patients, ranging from subtle mottling of the macular pigment epithelium (two patients) and a bull's eye maculopathy (seven patients) to macular chorioretinal atrophy (seven patients). CONCLUSIONS: Mutations in IMPG2 cause a severe form of RP with symptoms manifesting in the first 2 decades of life. IMPG2-associated RP is frequently accompanied by macular involvement, ranging from mild pigment alterations to profound chorioretinal atrophy. The resulting decrease in central vision in combination with the severe tunnel vision leads to severe visual impairment in patients with IMPG2-associated RP. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: To provide the first detailed clinical description in patients with RP caused by recessive mutations in IMPG2. METHODS: This international collaborative study includes 17 RP patients with inherited retinal disease caused by mutations in IMPG2. The patients were clinically (re-)examined, including extensive medical history taking, slit-lamp biomicroscopy, ophthalmoscopy, perimetry, ERG, optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, fundus photography, and color vision tests. The main outcome measures included mean age at onset, initial symptom, best-corrected visual acuity, fundus appearance, perimetry results, ERG responses, OCT images, FAF imaging, color vision test reports and DNA sequence variants. RESULTS: The mean age at onset was 10.5 years (range, 4-20 years). Initial symptoms included night blindness in 59% of patients, a decreased visual acuity in 35%, and visual field loss in 6%. Fundus abnormalities were typical of RP: optic disc pallor, attenuated vessels, bone spicules, and generalized atrophy of the retina and choriocapillaris. Additionally, we observed macular abnormalities in all patients, ranging from subtle mottling of the macular pigment epithelium (two patients) and a bull's eye maculopathy (seven patients) to macular chorioretinal atrophy (seven patients). CONCLUSIONS: Mutations in IMPG2 cause a severe form of RP with symptoms manifesting in the first 2 decades of life. IMPG2-associated RP is frequently accompanied by macular involvement, ranging from mild pigment alterations to profound chorioretinal atrophy. The resulting decrease in central vision in combination with the severe tunnel vision leads to severe visual impairment in patients with IMPG2-associated RP. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Caroline Brandl; Heidi L Schulz; Peter Charbel Issa; Johannes Birtel; Richard Bergholz; Clemens Lange; Claudia Dahlke; Ditta Zobor; Bernhard H F Weber; Heidi Stöhr Journal: Genes (Basel) Date: 2017-06-23 Impact factor: 4.096