[1] Childrens Hosp Philadelphia, Dept Neurol, Philadelphia, PA 19104 USA
[2] Univ Texas SW Med Ctr Dallas, Dept Pediat & Neurol, Dallas, TX 75390 USA
[3] Univ Iowa, Dept Pediat Neurol, Childrens Hosp, Iowa City, IA USA
[4] Washington Univ, Dept Neurol, St Louis, MO USA
[5] Cincinnati Childrens Hosp, Dept Pediat & Neurol, Cincinnati, OH USA
[6] Columbia Univ, Dept Neurol, New York, NY USA
[7] Univ Utah, Dept Neurol, Salt Lake City, UT USA
[8] Univ Utah, Dept Human Genet, Salt Lake City, UT USA