[1] Univ Texas, Hlth Sci Ctr, Dept Pediat, San Antonio, TX 78284 USA
[2] Univ Maryland, Sch Med, Dept Pediat, Baltimore, MD 21201 USA
[3] Univ Maryland, Sch Med, Dept Obstet & Gynecol, Baltimore, MD 21201 USA
[4] Univ Maryland, Sch Med, Dept Diagnost Radiol, Baltimore, MD 21201 USA
[5] St Jude Childrens Res Hosp, Dept Pathol & Lab Med, Memphis, TN 38105 USA
[6] Baylor Univ, Sch Med, Dept Pediat, Houston, TX 77030 USA
[7] Univ Florida, Sch Med, Dept Hlth Policy & Epidemiol, Gainesville, FL USA
[8] Pediat Oncol Grp, Stat Off, Gainesville, FL USA
[9] Childrens Mem Hosp, Div Hematol Oncol, Chicago, IL 60614 USA