[1] Paediat Res Unit, London SE1 9RT, England
[2] City Hope Natl Med Ctr, Div Human Genet, Duarte, CA 91010 USA
[3] Univ Calgary, Foothills Hosp, Div Hematol & Hematol Malignancies, Calgary, AB T2N 1N4, Canada
[4] Univ Bonn, Inst Expt Haematol & Blood Transfus, D-5300 Bonn, Germany
[5] Inst Clin Biochem, D-5300 Bonn 1, Germany
[6] Univ Amsterdam, Acad Med Ctr, Lab Expt Internal Med, NL-1105 AZ Amsterdam, Netherlands
[7] Natl Inst Hlth & Med Res, F-94010 Creteil, France
[8] Nara Med Coll, Dept Pediat, Nara, Japan
[9] Lab Fleury, Mol Biol Sect, BR-01333011 Sao Paulo, Brazil
[10] Univ Oxford, Sir William Dunn Sch Pathol, Oxford OX1 3RE, England