Affiliation: | 1. Department of Paediatrics, McGill University, Montreal, P. Q., Canada;2. Department of Ophthalmology, McGill University, Montreal, P. Q., Canada;3. Department of Neurology and Neurosurgery, McGill University, Montreal, P. Q., Canada;4. Department of Biology (Human Genetics), McGill University, Montreal, P. Q., Canada;5. Montreal Children''s Hospital, Montreal, P. Q., Canada |