1. Molecular Genetics Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland2Department of Biological Anthropology, Temple University, Philadelphia, Pennsylvania
2. Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
3. Molecular Genetics Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland
4. Department of Neurology, Helsinki University Central Hospital and Molecular Neurology, Research Programs Unit, Biomedicum, University of Helsinki, Helsinki, Finland
5. Molecular Genetics Unit, Department of Clinical Pathology, ASO OIRM–St Anna, Turin, Italy
6. Rita Levi-Montalcini Department of Neuroscience, University of Turin, Turin, Italy
7. Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland