HAEMOGLOBIN DISORDERS AMONG THE TRIBAL POPULATION "THE BAIGA" OF MADHYA PRADESH, INDIA By P. HEMACHANDRA REDDY A thesis submitted for the degree of Doctor of Philosophy in the University of London Perinatal Centre Department of Obstetrics and Gynaecology University College London Medical School London ProQuest Number: 10046204 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10046204 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 H:# ■’iwr THE BAIGA ABSTRACT In this study the prevalence and molecular nature of hereditary anaemias were studied in a primitive Central Indian tribe, the Baiga, in relation to socio-cultural, and environmental aspects and population structure. The entire population of 17 small villages was studied. "Normal red cell values" were defined, and 43% of the population appear to be iron deficient. Hereditary anaemia gene frequencies are, sickle cell 0.0824, G6PD deficiency (in males) 0.0457, B-thalassaemia 0.0057, and deletional a-plus thalassaemia 0.065. Both ^ and ^ deletions were observed and non-deletional a-thalassaemia was suspected. The over all gene frequencies of Xmn I polymorphism (C—>T -158 cap site; upstream of G gamma region) were 0.65 for - site 0.35 for + site and preferentially linked to 6^ genes. A theoretical basis has been established for mild sickle cell anaemia: high frequency of a- thalassaemia and the Xmn I 4- polymorphism, leading to a wide range of genotypes of different grades of severity. However, in the tribal environment there is a high early mortality among SS individuals and surviving SS individuals have low genetic fitness of SS compared to AA or AS. Higher fertility of ASxAA parents and lower mortality among their offspring suggest AS offspring continue to have a selective advantage against falciparum malaria. 34% of marriages were consanguineous. The figures suggest pre-reproductive mortality (up to 20 years) is higher among the offspring of consanguineous than of non- consanguineous couples. However, the difference was compensated by excess births related to a longer reproductive span among consanguineous couples. Viral markers for hepatitis B and C were studied. Tattooing, usual among the Baiga females had no observable effect on the prevalence of hepatitis. Methods developed in this study may be adapted to other tribal groups in India and elsewhere. CONTENTS Abstract Index to tables Index to figures Acknowledgements Glossary of terms Abbreviations Preface Chapter 1 ABORIGINALS IN INDIA 23 The difference between caste and tribe 23 Number of tribal groups 24 Numerical strength of tribal groups 24 Geographical distribution of tribals 24 Cultural classification 26 Racial affinities 28 Place of the Baiga 30 Madhya Pradesh 32 Chapter 2 THE BAIGA 33 Origin and racial affinities 33 Earlier descriptions of the Baiga 34 Baiga land 35 Geographical features and tribal environment 36 Agriculture 36 Sub-divisions of the tribe 39 Kinship pattern and terminology 40 Avoidance 44 Joking relations 44 Teknonimy 44 Marriage, kinship and family 44 Marriage payment 45 Polygamy 46 Divorce 46 Tattoo 47 Religious beliefs and practices 47 Bhagwan 48 Livelihood 49 Food and other dietary habits 51 Dress 52 Education 52 Health 52 Chapter 3 ASPECTS PARTICULARLY RELEVANT FOR THE STUDY: DEMOGRAPHY, SOCIAL CLASS, CONSANGUINEOUS MARRIAGE AND PREVALENCE OF MALARIA 54 Economic status 54 Consanguineous marriage 55 Lineage (kinship pattern) 56 Genetic aspects of consanguineous marriage 59 Admixture in inbreeding populations 59 Calculation of average inbreeding coefficient in human populations 60 Sterility 60 Smoking tobacco and drinking alcohol 60 Chewing tobacco 61 Prevalence of malaria 61 Chapter 4 HEREDITARY ANAEMIAS AND THEIR PREVALENCE AMONG THE ABORIGINALS IN INDIA 72 a-globin cluster 72 B-globin cluster 73 Regulation of haemoglobin production 73 Haemoglobin disorders 75 Malaria 76 Malaria in India 76 Sickle haemoglobinopathies 79 Historical development 79 Geographical distribution 79 Genetics of sickle gene 88 Sickle gene in Indian tribals 88 Pathophysiology of sickle cell disease 90 Sickle cell anaemia and clinical features in general 90 Clinical diversity 91 Clinical features: India 91 Genetic factors affecting the severity of the sickle cell disease 92 Sickle cell trait and malaria 94 Mechanism of protection against falciparum malaria 96 a-thalassaemia 98 a-thalassaemia syndromes 99 a-thalassaemia and malaria 99 B-thalassaemia 104 Dominant B-thalassaemia 104 Prevalence of B-thalassaemia 104 Studies on aboriginals 105 B-thalassaemia: India 111 Molecular studies: India 112 Glucose 6 phosphate dehydrogenase deficiency 113 The Human G6PD gene 115 Structure of human G6PD 116 G6PD and malaria 116 Geographical distribution 117 Health problems that can be caused by G6PD deficiency 117 G6PD deficiency in India 119 G6PD variants in India 123 AIMS AND OBJECTIVES OF THE STUDY 125 Chapter 5 METHODS OF THE STUDY POPULATION, MATERIALS AND METHODS 127 Activities in the field 127 Research team 127 Transport 127 Time of data collection 127 Interpreter’s help 127 Selection of area 128 Population 128 Demographic/Anthropological data collection, field 131 Establishing a rapport in the field 131 Field experiences 133 Where to stay in the tribal area during field work 134 Demographic data 134 Analysis of data 137 Haematological methods, field laboratory 137 Red cell indices CBC 5 portable Coulter Counter 140 Zinc Protofluor machine for screening iron deficiency 142 Fluorescence spot method for G6PD deficiency screening 142 Haematological methods, Jabalpur 147 Haemoglobin electrophoresis 148 Micro-column chromatography 148 Haematological methods, London 149 Isoelectric focusing 149 Serum ferritins 149 Hb F Assay, Betke method (Dacie and Lewis 1991) 150 Quantitation of Hb A 2 150 Hepatitis screening 150 DNA methods, Jabalpur and London 150 Mouthwash DNA 151 Gene analysis, London 153 Xmn I polymorphism 154 Sickle cell mutation 156 a-thalassaemia 158 G6PD deficiency, gene analysis 158 Chapter 6 DEMOGRAPHIC DATA: RESULTS AND DISCUSSION 160 Population, age and sex distribution 160 Mortality 160 Fertility 168 Maternal age distribution and fertility 168 Mate choice and family name 169 Marital distance and gene flow 169 Age at menarche 170 Age at marriage 182 Trends in age at marriage 182 Marriage and first conception 182 Age difference in spouses 182 Marriage practice 182 Trends in cousin marriage 183 Polygamy 183 Divorce 184 Twinning 184 Infertility 184 Breast feeding 184 Contraception 184 Education 192 Smoking tobacco 192 Chewing tobacco 192 Drinking alcohol 192 DISCUSSION 192 Chapter 7 HAEMATOLOGICAL AND DNA STUDIES: RESULTS AND DISCUSSION 202 Haematological parameters 202 Hereditary anaemias 222 Haemoglobin S 227 6-thalassaemia 227 G6PD deficiency 228 DNA studies 228 a-thalassaemia 228 Xmn I polymorphism 228 G6PD deficiency 229 DISCUSSION 229 Chapter 8 FAMILY STUDIES: RESULTS AND DISCUSSION 235 Sickle haemoglobin and mortality 246 Sickle haemoglobin and parenthood 247 Sickle haemoglobin, malaria and mortality 252 G6PD deficiency, fertility and mortality 252 DISCUSSION 253 Chapter 9 VIRAL MARKERS 254 Hepatitis viral markers 254 Results 255 GENERAL DISCUSSION AND CONCLUSIONS 256 APPENDICES 260 Appendix 1 260 Appendix 2 263 REFERENCES 267 INDEX TO TABLES Table 1.1 Tribes and their numerical strength (source census 1981) 25 Table 3.1 Marriage practice in North-Eastern India (Jayant Sarkar 1988) 57 Table 3.2 Data on incidence of consanguineous marriage in India 64 Table 3.3 Possible inbreeding coefficients in different mating patterns in Humans 68 Table 3.4 Prevalence of malarial parasites in peripheral blood in Baiga villages 69 Table 3.5 Prevalence of malaria in the study villages 70 Table 4.1 Six distinct haemoglobins are produced during development 73 Table 4.2 Abnormal haemoglobins in India 78 Table 4.3 Major common haemoglobin disorders 79 Table 4.4 Prevalence of sickle cell gene in tribals in India 80 Table 4.5 Prevalence of haemoglobin E 87 Table 4.6 Haematological findings in SS patients in India 95 Table 4.7 6-globin haplotypes, Hb F levels and ages of SS and SB® thal. patients (Kulozik et al 1987) 95 Table 4.8 Xmn I polymorphic site and fetal haemoglobin in Asians (Thein et al 1986, Winichagoon et al 1993) 96 Table 4.9 Sickle haemoglobin, mortality and fertility in African populations (Allison 1956) 97 Table 4.10 Growth of malarial parasites in vitro 98 Table 4.11 Haematological findings in individuals with a-thalassaemia 102 Table 4.12 Non-deletion mutation that cause a-thalassaemia 103 Table 4.13 a-thalassaemia in tribal populations in India 105 Table 4.14 6-thalassaemia point mutations (Baysal 1992) 106 Table 4.15 Deletions causing 6-thalassaemia (Baysal 1992) 110 Table 4.16 Distribution of 6-thalassaemia in relation to AS & SS in aboriginals in India 111 Table 4.17 6-thalassaemia mutations in non-tribals in India 112 Table 4.18 Exon and intron sizes in the human G6PD gene 119 Table 4.19 Prevalence of G6PD deficiency (in males) in aboriginal groups 120 Table 4.20