[1] Univ Maryland, Sch Med, Dept Pediat, Div Human Genet, Baltimore, MD 21201 USA
[2] Childrens Natl Med Ctr, Dept Neurol, Washington, DC 20010 USA
[3] Childrens Natl Med Ctr, Med Genet Res Ctr, Washington, DC 20010 USA
[4] USDA, Alexandria, VA USA
[5] Univ Maryland, Sch Social Work, Baltimore, MD 21201 USA
[6] Genet Alliance, Washington, DC USA
[7] US Hlth Resources & Serv Adm, US Dept HHS, Maternal & Child Hlth Bur, Rockville, MD 20857 USA
[8] Univ Maryland, Sch Pharm, Dept Pharmaceut Hlth Serv Res, Baltimore, MD 21201 USA