[1] Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, Dept Microbiol & Immunol, San Francisco, CA 94143 USA
[5] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[6] Duke Univ, Med Ctr, Dept Med, Ctr Human Genet, Durham, NC USA
[7] Vanderbilt Univ, Dept Mol Physiol & Biophys, Program Human Genet, Nashville, TN 37232 USA