[1] Univ Witwatersrand, Dept Mol Med & Haematol, NHLS, Johannesburg, South Africa
[2] Univ Witwatersrand, Sch Pathol, Johannesburg, South Africa
[3] Chris Hani Baragwanath Hosp, Clin Haematol Unit, Johannesburg, South Africa
[4] Univ Witwatersrand, Dept Med, Fac Hlth Sci, ZA-2001 Johannesburg, South Africa
[5] St Johns Eye Hosp, Dept Opthalmol, Johannesburg, South Africa
[6] Tygerberg Acad Hosp, Div Clin Haematol, Dept Med, Cape Town, South Africa
[7] Univ Orange Free State, Dept Haematol & Cell Biol, NHLS Univ Tertiary Labs, Bloemfontein, South Africa
[8] Red Cross War Mem Childrens Hosp, Cape Town, South Africa
[9] Univ Cape Town, ZA-7700 Rondebosch, South Africa
[10] Chris Hani Baragwanath Hosp, Dept Cardiol, Johannesburg, South Africa
[11] Univ Cape Town, Fac Hlth Sci, Dept Pathol & Med, Div Haematol, ZA-7700 Rondebosch, South Africa
[12] Charlotte Maxeke Johannesburg Acad Hosp, Dept Paediat Haematol Oncol, Johannesburg, South Africa