[1] NHGRI, Social & Behav Res Branch, Bethesda, MD 20892 USA
[2] Univ Michigan, Sch Publ Hlth, Dept Hlth Behav & Hlth Educ, Ann Arbor, MI 48109 USA
[3] Boston Univ, Sch Publ Hlth, Data Coordinating Ctr, Boston, MA USA
[4] Boston Univ, Sch Med, Dept Neurol, Boston, MA 02118 USA
[5] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[6] Boston Univ, Sch Med, Dept Med Genet, Boston, MA 02118 USA