1. Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
2. Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, Scotland, United Kingdom
3. Center for Hereditary Retinal Degenerations, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
4. Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
5. Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
6. Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom