1. Department of Chemical Pathology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
2. Letten Foundation Research House, Harare, Zimbabwe.
3. Department of Immunology, University of Zimbabwe, Harare, Zimbabwe.
4. Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
5. Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
6. Institute of Clinical Medicine, University of Oslo and Womens' Clinic, Rikshospitalet, University Hospital, Oslo, Norway.