[1] Georgetown Univ Hosp, Dept Neurosurg, Washington, DC 20007 USA
[2] Childrens Natl Med Ctr, Div Pediat Neurosurg, Washington, DC 20010 USA
[3] Childrens Natl Med Ctr, Ctr Canc & Blood Disorders, Washington, DC 20010 USA
[4] Childrens Natl Med Ctr, Res Ctr Genet Med, Washington, DC 20010 USA