1. Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., A3-025, PO Box 19024; Seattle WA 98109-1024 USA
2. Present address: Boehringer Ingelheim Pharma KG, Genomics Group, Birkendorfer Strasse 65; D-88397 Biberach an der Riss Germany
3. Department of Genetics, Harvard Medical School, 200 Longwood Avenue; Boston MA 02115 USA
4. Department of Neurology, University of Washington Medical School; Seattle WA 98195 USA
5. Department of Radiation Oncology, University of Washington Medical School; Seattle WA 98195 USA