[1] Univ Texas South Western, Dept Internal Med, Dallas, TX USA
[2] Univ Texas South Western, Dept Pediat, Dallas, TX USA
[3] Natl Inst Hlth, Hematol Branch, Natl Heart Lung & Blood Inst, Bethesda, MD USA
[4] Univ Texas South Western, Div Hematol & Oncol, Dept Internal Med, Dallas, TX USA
[5] Univ Texas South Western, Dept Pathol, Dallas, TX USA