[1] UNIV CALIF, DEPT PEDIAT, LOS ANGELES, CA USA
[2] UNIV CALIF, DEPT BIOMATH, LOS ANGELES, CA USA
[3] UNIV CALIF, DEPT PSYCHIAT, LOS ANGELES, CA USA
[4] UNIV N CAROLINA, DEPT BIOSTATISTICS, CHAPEL HILL, NC USA
[5] UNIV N CAROLINA, GENET CURRICULUM, CHAPEL HILL, NC USA