[1] YALE UNIV, SCH MED, DEPT PEDIAT HUMAN GENET & INTERNAL MED, NEW HAVEN, CT 06510 USA
[2] TUFTS UNIV, ST ELIZABETHS HOSP, SCH MED, DEPT BIOMED RES, BOSTON, MA 02135 USA
[3] HOP BEAUJON, INSERM, U160, F-92118 CLICHY, FRANCE
[4] WASHINGTON UNIV, SCH MED, DEPT PEDIAT, ST LOUIS, MO 63110 USA
[5] HOP ST LOUIS, F-75010 PARIS, FRANCE
[6] THOMAS JEFFERSON UNIV, CARDEZA FDN HEMATOL RES, DEPT MED, PHILADELPHIA, PA 19107 USA
[7] UNIV WITWATERSRAND, S AFRICAN INST MED RES, DEPT HAEMATOL, JOHANNESBURG 2193, SOUTH AFRICA