[1] CHOC Childrens Hosp, Dept Res Adm, Orange, CA USA
[2] Duke Univ, Dept Pediat, Sch Med, Durham, NC 27706 USA
[3] Iowa State Univ, Dept Anim Sci, Ames, IA USA
[4] CHOC Childrens Hosp, Orthoped Inst, Orange, CA USA
[5] Washington Univ, Dept Pediat, Sch Med St Louis, St Louis, MO 63130 USA
[6] CHOC Childrens Specialists, Div Metab Disorders, Orange, CA USA