[1] Vanderbilt Univ, Med Ctr, Nashville, TN 37235 USA
[2] Ohio State Univ, Nationwide Childrens Hosp, Columbus, OH USA
[3] UPMC Childrens Hosp, Pittsburgh, PA USA
[4] Stanford Univ, Palo Alto, CA USA
[5] Hosp Guillermo Almenara Irigoyen, Lima, Peru
[6] Cincinnati Childrens Hosp, Med Ctr, Cincinnati, OH USA
[7] Geneva Univ Hosp, Childrens Hosp Geneva, Fac Med, Geneva, Switzerland
[8] Univ Cape Town, Red Cross War Mem Childrens Hosp, Cape Town, South Africa
[9] Univ Zurich, Fac Med, Zurich, Switzerland