[1] Alfred I DuPont Hosp Children, Div Pediat Gastroenterol Hepatol & Nutr, Wilmington, DE 19803 USA
[2] Penn State Univ, Dept Pediat, Penn State Childrens Hosp, Hershey, PA USA
[3] Penn State Univ, Div Pediat Neurol, Dept Pediat, Penn State Childrens Hosp, Hershey, PA USA