1. A. A. T. Geisterfer-Lowrance, M. Christe, D. A. Conner, J. G. Seidman, Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
2. J. S. Ingwall, Department of Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
3. F. J. Schoen, Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
4. C. E. Seidman, Howard Hughes Medical Institute, Brigham and Women's Hospital, 75 Francis Street, Boston MA 02115, USA.