1. From the Departments of Neurology (W.T.L.), Epidemiology (W.T.L.), Biostatistics (A.M.A.), and Radiology (N.J.B.), University of Washington, Seattle, WA; Department of Epidemiology (L.H.K.), University of Pittsburgh, Pittsburgh, PA; Cleveland Clinic Lou Ruvo Center for Brain Health (C.B.), Las Vegas, NV; Department of Neurology (D.S.L.), Wake Forest University School of Medicine, Winston-Salem, NC; Office of Population Genomics (T.A.M.), National Human Genome Research Institute, Bethesda, MD.