1. Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
2. Department of Neurology, University of Washington, Seattle, WA 98105, USA
3. Department of Radiology, Seattle Children’s Hospital, Seattle, WA 98105, USA
4. Department of Radiology, University of Washington, Seattle, WA 98105, USA
5. Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
6. Department of Human Genetics, Leiden University Medical Center, 2333, Leiden, The Netherlands
7. Department of Neurology, University of Kansas Medical Center, Kansas City, KA 66160, USA