[1] Singapore Gen Hosp, Dept Haematol, Haematol Lab, Singapore 169608, Singapore
[2] WWU, Inst Humangenet, Munster, Germany
[3] UKM Munster, Munster, Germany
[4] Singapore Gen Hosp, Dept Clin Res, Singapore 169608, Singapore
[5] WWU, Inst Med Biochem, Munster, Germany