[1] Johns Hopkins Univ, Sch Med, Dept Med, Div Hematol, Baltimore, MD 21205 USA
[2] Vanderbilt Univ, Med Ctr, Div Transfus Med, Nashville, TN USA
[3] Vanderbilt Univ, Med Ctr, Div Hematol, Nashville, TN USA
[4] Univ Texas Southwestern Med Ctr Dallas, Div Hematol Oncol, Dept Med, Dallas, TX 75390 USA
[5] Univ Miami, Miller Sch Med, Dept Obstet Gynecol & Reprod Sci, Miami, FL 33136 USA
[6] Cincinnati Childrens Hosp, Div Pediat Hematol, Dept Pediat, Cincinnati, OH USA
[7] Duke Univ, Div Maternal Fetal Med, Dept Obstet & Gynecol, Div Hematol,Dept Med, Durham, England
[8] Childrens Hosp Philadelphia, Div Hematol, Philadelphia, PA 19104 USA