[1] SW Fdn Biomed Res, Dept Genet, San Antonio, TX 78245 USA
[2] GlaxoWellcome Inc, Res Triangle Pk, NC USA
[3] N Carolina State Univ, Dept Stat Genet, Raleigh, NC 27695 USA
[4] Columbia Univ, Columbia Genome Ctr, New York, NY USA
[5] Columbia Univ, Dept Psychiat, New York, NY USA