1. From the Neurological Institute (T.R., M.S.E., J.P., B.B-A., R.L.S.) and Genome Center (S-H.H.J.), Columbia University, New York, NY, and Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Department of Medicine, Royal Free and University College London, Medical School, London, UK (S.M., S.E.H.).