[1] Univ Stellenbosch, Div Haematol, Cape Town, South Africa
[2] Univ Stellenbosch, Dept Pathol, Cape Town, South Africa
[3] Univ Witwatersrand, Sch Pathol, Div Mol Med & Haematol, Natl Hlth Lab Serv, Johannesburg, South Africa
[4] Univ Witwatersrand, Sch Pathol, Div Anat Pathol, Natl Hlth Lab Serv, Johannesburg, South Africa
[5] Ohio State Univ, Dept Pathol, Columbus, OH 43210 USA