[1] HARVARD UNIV, CHILDRENS HOSP, MED CTR, SCH MED, DEPT PATHOL, BOSTON, MA 02115 USA
[2] HARVARD UNIV, CHILDRENS HOSP,MED CTR,SCH MED, DEPT NEUROL NEUROPATHOL, BOSTON, MA 02115 USA
[3] HARVARD UNIV, CHILDRENS HOSP, MED CTR, CTR RES MENTAL RETARDAT, BOSTON, MA 02115 USA
[4] HARVARD UNIV, SCH PUBL HLTH, DEPT BIOSTAT, BOSTON, MA 02115 USA