1. Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
2. Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
3. Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
4. Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands