[1] Complete Genom Inc, Mountain View, CA 94043 USA
[2] Harvard Univ, Sch Med, Dept Genet, Boston, MA 02115 USA
[3] Boston Univ, Program Bioinformat, Boston, MA 02215 USA
[4] Harvard Univ, Sch Med, Wyss Inst Biologically Inspired Engn, Cambridge, MA 02115 USA