1. Institute for Molecular Genetics, Baylor College of Medicine, Houston, TX 77030.
2. Section of Cardiology, Baylor College of Medicine, Houston, TX 77030.
3. Institute for Molecular Genetics and Human Genome Center, Baylor College of Medicine, Houston, TX 77030.
4. Department of Neurology, Baylor College of Medicine, and Veterans Administration Medical Center, Houston, TX 77030.
5. Istituto di Clinica Neurologica, Universita di Milano, 20122, Milan, Italy.
6. Institute for Molecular Genetics and Howard Hughes Medical Institute, Human Genome Center, Baylor College of Medicine, Houston, TX 77030.