Sickle Cell Aneamia in Cameroon
Total Page:16
File Type:pdf, Size:1020Kb
Sickle Cell Anaemia in Cameroon: Co-Inheritance of α- Thalassemia, HBB Gene Haplotypes, Clinical & Haematological Characterisation s MARYAM RUMANEY (RMNMAR005) MSc in Human Genetics University of Cape Town FACULTY OF HEALTH SCIENCES SUPERVISED BY: Associate Professor Ambroise Wonkam CO-SUPERVISED BY: Ms Anna Alvera Vorster, and Professor Raj Ramesar 1 The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town DECLARATION I, MISS MARYAM BIBI RUMANEY, hereby declare that the work on which this dissertation/thesis is based is my original work (except where acknowledgements indicate otherwise) and that neither the whole work nor any part of it has been, is being, or is to be submitted for another degree in this or any other university. I empower the university to reproduce for the purpose of research either the whole or any portion of the contents in any manner whatsoever. Signature:__________Date: 25 May 2015 2 ACKNOWLEDGEMENTS "Smooth seas do not make skilful sailors." - African Proverb First, I acknowledge my Lord, my Creator, Allah, for giving me the strength to complete this study. It was through His Guidance and Mercy that I was able to succeed. I would like to express my warmest gratitude to my wonderful parents, Ismail Cassiem and Suraya Rumaney, and brothers, Hishamuddin and Nizamuddin Rumaney, who have supported me unconditionally in all my endeavours in life. To my amazing family, my uncles and aunts, Nazier Cassiem, Fowzia Cassiem, Zuleigha Desai, Basheer Desai, Nurjehaan Cassiem, Mumtaz Rumanay and Zeenat Khan, thank you for all the support that you have given me throughout this process, it is deeply appreciated and will never be forgotten. To my supervisors Ambroise Wonkam, Anna Alvera Vorster and Raj Ramesar, thank you for the time, effort, advice and support offered. Your input has been invaluable and this study would not have been possible without your help, commitment, dedication, motivation and zeal. To my colleague, Ngo Bitoungui Valentina Josiane, thank you for your support, help and for going that extra mile. It is valued beyond measure. Working with you has been an enriching experience. I would like to thank the NRF-DAAD for funding my degree for 2013, and the University of Cape Town (UCT) and the Medical Research Council of South Africa (MRC) for covering the research costs. To Professor Amanda Krause and Fahmeeda Essop from the National Health Laboratory of Science (NHLS), and Professor Samuel Chong from the National University of Singapore (NUS), thank you for supplying the control DNA. To Professor Andre Pascal Kengne at the MRC, South Africa, thank you for your help and expertise with the statistical analysis utilised in this study. Your guidance has been exceptional. Lastly, to all my colleagues at the Division of Human Genetics at UCT, thank you for the support, motivation, and kindness that you have shown me. 3 Table of Contents ABBREVIATIONS ....................................................................................................................... 10 SUMMARY .................................................................................................................................... 11 CHAPTER 1: INTRODUCTION ............................................................................................... 13 CHAPTER 2: LITERATURE REVIEW .................................................................................... 15 2.1 SICKLE CELL ANAEMIA (SCA) ..................................................................................................................... 15 2.1.1 EPIDEMIOLOGY........................................................................................................................................ 15 2.1.2 MOLECULAR AND CLINICAL MANIFESTATIONS OF SCA .......................................................................... 16 2.1.4 HAPLOTYPES OF THE HBB GENE .............................................................................................................. 22 2.2 ALPHA-THALASSEMIA (α-thalassemia) ..................................................................................................... 26 2.2.1 EPIDEMIOLOGY........................................................................................................................................ 26 2.2.2 MOLECULAR AND CLINICAL MANIFESTATIONS OF α-THALASSEMIA ...................................................... 27 2.2.4 ALPHA-THALASSEMIA: A GENETIC MODIFIER OF SCA ............................................................................. 29 2.3 ROLE OF MALARIA ................................................................................................................................... 30 2.4 STUDY RATIONALE: .................................................................................................................................. 33 2.5 AIM AND OBJECTIVES: ............................................................................................................................. 34 CHAPTER 3: MATERIALS AND METHODS ......................................................................... 35 3.1 ETHICAL CONSIDERATION ........................................................................................................................ 35 3.2 STUDY DESIGN ......................................................................................................................................... 35 3.3 RESEARCHER’S ROLE ................................................................................................................................ 35 3.4 RESEARCH SETTING AND CLINICAL DATA COLLECTION ............................................................................. 36 3.5 SAMPLE/PATIENT INFORMATION ............................................................................................................ 36 3.6 LEVEL OF PATIENT CARE ........................................................................................................................... 38 3.7 HbF DETECTION ........................................................................................................................................ 38 3.7.1. ALKALI DENATURATION TEST (ADT) ....................................................................................................... 39 3.7.2 HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) .................................................................... 40 3.8 DNA EXTRACTION .................................................................................................................................... 40 3.8.1 Rationale ................................................................................................................................................. 40 3.8.2 Method .................................................................................................................................................... 41 4 3.8.3 Principle ................................................................................................................................................... 41 3.9 PHASE I: MOLECULAR DIAGNOSTIC TESTING FOR SCA (HbSS) .................................................................. 43 3.9.1 Rationale ................................................................................................................................................. 43 3.9.2 Method .................................................................................................................................................... 43 3.9.3 Principle ................................................................................................................................................... 43 3.9.4 Expected fragment sizes .......................................................................................................................... 45 3.10 PHASE II: HAPLOTYPING OF THE HBB GENE ............................................................................................ 45 3.10.1 Rationale ............................................................................................................................................... 45 3.10.2 Method .................................................................................................................................................. 45 3.10.3 Principle ................................................................................................................................................. 45 3.10.4: Expected fragment sizes....................................................................................................................... 50 3.10.5: Haplotype determination ..................................................................................................................... 50 3.11 PHASE III: α-THALASSEMIA DELETION SCREENING ................................................................................. 51 3.11.1 Rationale ............................................................................................................................................... 51 3.11.2 Method .................................................................................................................................................