Gautam K. Kshatriya

Genetic Affinities of the Siddis of South India: An Emigrant Population of East Africa

Abstract Historical records indicate that the Portuguese brought the African Siddis to Goa, India, as slaves about 500 years ago. Subsequently, the Siddis moved into the interior regions of the state of Karnataka, India, and have remained there ever since. Over time the Siddis have experienced considerable cultural changes because of their proximity to neighboring population groups. To understand the biological consequences of these changes, we studied the Siddis to determine the extent of genetic variation and the contributions from the African, European, and Indian ancestral populations. In the present study we typed the Siddis for 20 polymorphic serological, red cell, and Alu insertion-deletion loci. The overall pattern of phenotype (and genotype) distribution is in accordance with Hardy-Weinberg expectations. Considering the ethnohistorical records and the availability of secondary-source genetic data, we used two data sets in the analysis: one comprising eight serological and red cell enzyme markers with eight population groups and another comprising six Alu insertion-deletion markers with seven tribal groups of South India. The dendrograms generated from these two data sets on the basis of genetic distance analysis between the selected populations of African, European, and Indian descent reveals that the Siddis are closer to the Africans than they are to the South Indian populations. Genetic admixture analysis using a dihybrid model (19 loci) and a trihybrid model (10 loci and 8 loci) shows that the predominant influence comes from the Africans, a lesser contribution from the South Indians, and a slight contribution from the Portuguese. Thus the original composition of the African genes among the Siddis has been diluted to some extent by the contribution from southern Indian population groups. There is no nonrandom association of alleles among a set of 10 genetic marker systems considered in the present study. The demonstration of genetic homogeneity of the Siddis, despite their admixed origin, suggests the utility of this population for genetic and epidemiological studies.

Fertility and mortality differentials among selected tribal population groups of North-Western and eastern India

Selection potential based on differential fertility and mortality has been computed for six tribal groups inhabiting different geo-climatic conditions, namely: Sahariya, Mina and Bhil of the State of Rajasthan, north-western India, and Munda, Santal and Lodha of the State of West Bengal, eastern India. Irrespective of the methodology, the total index of selection was found to be highest among Lodhas (0.668), followed by Sahariyas (0.524), Santals (0.462), Bhils (0.386), Mundas (0.353) and Minas (0.334). Incidentally, Lodha and Sahariya are two of the seventy-four notified primitive tribal groups of India, and these two study populations show the highest index of total selection, mainly because of a higher embryonic and postnatal mortality. The relative contribution of the fertility component to the index of total selection is higher than the corresponding mortality component in all tribal groups. The analysis of postnatal mortality components indicates that childhood mortality constitutes the bulk of postnatal mortality, suggesting that children under 5 years need better health care in these tribal groups.

Genomic congruence of Indo-European speaking tribes of western India with Dravidian-speaking populations of southern India: A study of 20 autosomal DNA markers

Background: Due to its geographic location, Gujarat has played a major role in assimilation of different cultures with those of the subcontinent of India and is home to a number of Indo-European speaking tribes. Aim: This study examined the genetic structure and extent of gene differentiation in eight Indo-European speaking tribal populations of southern Gujarat in western India. It also determined if there was any residual effect of linguistic and cultural assimilation of Indo-European speaking groups on the genomic profile of the tribes under study. Methods: Twenty autosomal DNA markers (Alu InDels and Restriction Fragment Length Polymorphisms) were analysed. Results and conclusions: Average heterozygosity levels were high and degree of gene differentiation (GST = 2%) was small, indicating that genetic drift may not have played a major role in bringing out a characteristic genetic differentiation in these groups. The genetic structure of the populations revealed that neither of these groups was overtly admixed nor completely isolated. Other analyses undertaken on the population affiliations revealed only a slight influence of Indo-European speaking populations on the tribal groups of Gujarat, but there was an overwhelming influence of Dravidian speaking groups of southern India, suggesting that genetic affinities may not necessarily be dependent on linguistic similarities.

Triple Burden of Obesity, Undernutrition, and Cardiovascular Disease Risk among Indian Tribes

Background Socio-cultural transitions among individuals from vulnerable groups introduce epidemiological transition, with a concomitant increase in the prevalence of undernutrition, obesity, and cardiovascular disease risks. An accepted conventional wisdom exists for Indian tribes that they are undernourished and away from lifestyle-related diseases. However, the extent of this triple burden affecting them is unknown. In this study, we assessed this triple burden among the 9 major tribes of India. Methods and Findings During January 2011 to December 2013, we conducted a cross-sectional study among 1066 men and 1090 women constituting a total of 2156 adults belonging to the 9 major tribal groups: Santals, Oraons, and Koras (West Bengal); Santals, Bhumijs, and Bathudis (Odisha); and Dhodias, Kuknas, and Chaudharis (Gujarat) to estimate the prevalence of the triple burden (undernutrition, overweight or obesity, and hypertension). A high prevalence of undernutrition and hypertension was observed among the Koras (51.9%and 10.6%, respectively), Bathudis (51.3% and 12.1%, respectively), and Oraons (49.6% and 16.5%, respectively). However, the prevalence of overweight and hypertension among the Bhumijs (17.7% and 14.7%, respectively), Dhodias (23.8% and 12.9%, respectively), Kuknas (15.8% and 11.3%, respectively), and Santals of West Bengal (12.2% and 11.8%, respectively) and Odisha (15% and 9.6%, respectively) was most alarming. The prevalence of overweight or obesity among the women was 10.9% and 1.5%, respectively, with 14.0% hypertensive women. The prevalence of overweight and obesity among the men was 14.8% and 1.7%, respectively, with 9.2% hypertensive men. Undernutrition was highly prevalent among men and women. However, data from the past 30 years on systolic blood pressure (SBP) and body mass index (BMI) revealed that the studied tribes were at a higher risk than the general Indian population. In addition, a vast gender disparity with relation to the disease and risk prevalence was observed. Conclusion The alarming trend of an increasing prevalence of overweight/obesity, undernutrition, and hypertension is observed among indigenous populations of India, emphasizing the incorporation of a specific health management policy.

Genomic and Linguistic Affinities: A Study of Allelic and Haplotype Diversity at DRD2 Locus Among the Tribes of Gujarat, Western India

Do genetic and linguistic affinities necessarily go hand in hand? An attempt has been made in the present work to explore this dimension of population structure using three evolutionarily important TaqI sites (TaqI A, TaqI B, and TaqI D) on the dopamine receptor D2 (DRD2) locus. For the first time, DNA samples from 612 unrelated individuals belonging to 11 Indo-European-speaking tribal population groups of Gujarat, western India, have been analyzed for these three sites. All the three sites are found to be polymorphic with greater interpopulation variation seen at the TaqI B site. The average heterozygosity for the haplotype system has been found to be high in the populations under study. Most of the populations share six of the eight haplotypes pointing toward underlying genetic uniformity, which is further reaffirmed by regression analysis of heterozygosity on genetic distance. The frequency of ancestral haplotype B2D2A1 is found to range between 1.9% and 15.9%. Linkage disequilibrium between TaqI B and TaqI D sites and between TaqI B and TaqI A sites is statistically significant in all but one population. Our findings reveal strong affinities between Indo-European-speaking tribal groups of Gujarat and Dravidian-speaking tribal groups of South India, suggesting that genetic affinities may not necessarily be dependent on linguistic similarities.

Fertility and Mortality Differentials among the Population Groups of the Himalayas

Selection potential based on differential fertility and mortality has been computed for 24 Himalayan populations classified into four groups: Himalayan populations with Asian affinities (HPA), Brahmans, Rajputs, and Scheduled Castes (Shilpkars). Irrespective of the methodology followed, the total index of selection was found to be highest (0.794) in Barbatiyas (HPA) and lowest (0.428) in Rajputs. The relative contribution of fertility component (If) to the index of total selection (It) is higher than the corresponding mortality component (Im) in all 24 groups. An analysis of correlation and regression on different components of the indices of selection performed among these 24 Himalayan populations revealed that the contributions of If in determining It are stronger than Im. Further, both If and Im are strongly associated with It and account for 76% and 67% of total variability in It, respectively. Examination of the relationship of the selection potential with the differential altitude and social categories showed a decrease in the index from high altitude to low altitude. Similarly, an inverse relationship was found between various indices and social categories. Himalayan populations with Asian affinities (HPA) in the present study reveal higher values of selection potential. Interestingly, these populations invariably reside in high altitude areas where health and communication infrastructures are poorly developed. Thus, the differential pattern of fertility and mortality among the Himalayan populations indicates that they are passing through a stage of transition, as is evident from the decrease in various selection indices. It is also apparent that groups that are less developed socioeconomically, as well as those inhabiting high altitude regions, are lagging behind in this process.

Genomic Structure of the Immigrant Siddis of East Africa to Southern India: A Study of 20 Autosomal DNA Markers

The Siddis are a tribal group of African origin living in Karnataka, India. They have undergone considerable cultural change due to their proximity to neighboring population groups. To understand the biological consequences of these changes, we describe the genomic structure of the Siddis and the contribution from putative ancestral populations using 20 autosomal DNA markers. The distribution of Alu indel markers and a genetic distance analysis reveals their closer affinities with Africans. The levels of genomic diversity and heterozygosity are high in all the populations of southern India. Genetic admixture analysis reveals a predominant contribution from Africans, a lesser contribution from south Indians, and a slight one from Europeans. There is no evidence of gametic disequilibrium in the Siddis. The genetic homogeneity of the Siddis, in spite of its admixed origin, suggests the utility of this population for genetic epidemiological studies.

Natural selection among Kinnaura of the Himalayan highland: A comparative analysis with other Indian and Himalayan populations

The present investigation on fertility and mortality differential among Kinnaura of the Himalayan highland is based on data collected from 160 post-menopausal women belonging to the middle and high altitude region of Kinnaur district of Himachal Pradesh (Indian Himalayas). Selection potential based on differential fertility and mortality was computed for middle-and high-altitude women. Irrespective of the methodology, the total index of selection was found to be highest among middle-altitude women (0.386) as compared with high-altitude (0.370) women, whereas for the total population it is estimated to be 0.384. It was found that the Kinnaura of the Himalayan highland showing moderate index of total selection and relative contribution of the mortality component (Im) to the index of total selection is higher than the corresponding fertility component (If). The analysis of embryonic and post-natal mortality components shows that the post-natal mortality components are higher in comparison with the embryonic mortality components among highlanders and needs special intervention and health care. The present findings are compared with other Indian tribes as well as non-tribes of the Himalayan region and other parts of the country. It reveals that this index among Kinnaura is moderate than the other population groups; among the Himalayan population, the highest was reported for Galong (It = 1.07) of Arunachal, whereas the lowest was reported from Ahom (It = 0.218) of Manipur. The correlation and regression analysis between total index of selection (It) and fertility (If) and mortality (Im) components for pooled data of populations of the Indian Himalayan states show that If and Im account for 21.6 and 29.1% variability, respectively. In Crows total index of selection (It) along with strong association, which is significant at the 1% level, this indicates that mortality plays a greater role in natural selection in comparison with fertility among populations of the Indian Himalayas.

Gender Disparities in the Prevalence of Undernutrition and the Higher Risk among the Young Women of Indian Tribes.

Background High undernutrition is a grave concern in India. Marginalized populations like Indian tribes have been under the serious stress of such nutritional extreme. Women, in particular, are the worst sufferers. Gender-related comprehensive studies regarding the prevalence and risks of undernutrition among the tribes have not been properly pursued in India; the vulnerability of the young females has least been examined. Methods and Findings We conducted a cross-sectional study during January 2011 to December 2013 among 1066 males and 1090 females (n = 2156) in the 20–60 years age group belonging to the nine major tribes; Santals, Oraons and Koras (West Bengal): Santals, Bhumijs and Bathudis (Odisha): Dhodias, Kuknas and Chaudharis (Gujarat). The undernutrition burden was estimated and such risks were analyzed for the women in comparison to the men. The overall undernutrition among the females was found to be 47.4% (95% CI 44.4–50.4) against 32.1% (95% CI 29.3–34.9) among males, indicating about a half of the female population undernourished. The odds of risks for underweight status among females were observed to be high in comparison to males with an odds of 1.9 (95% CI, 1.6–2.2; p≤0.001) for the overall undernutrition category, 1.7 (95% CI, 1.3–2.3; p≤0.001) for the mild undernutrition category, 1.3 (95% CI, 1.1–1.6; p≤0.01) for combined moderate and mild undernutrition category and 3.3 (95% CI at 2.3–4.6; p≤0.001) for severe undernutrition category. The young females were observed with a high prevalence of undernutrition along with increased risk. The 30-year mean BMI trend of the Indian population in comparison to the males, females, and overall tribal population places the tribal females at the highest risk. Conclusion Indian tribes are suffering from the higher prevalence of undernutrition by further highlighting a high gender bias. The health and empowerment of adolescent and young tribal girls needs additional focus. Overall, no remarkable control on undernutrition has been achieved among Indian tribes despite various efforts.

Homogeneity of Maternal Perception of Her Child's Weight in Northeastern Mexico

Abstract The objectives were to assess a maternal perception of her child’s weight through two tests, words, and images, to validate tests; and to compare perception among Mexican populations. Participants 2,842 mother– child dyads; the child’s body mass index measurement was the gold standard. Sensitivity, specificity, Kappa value, Z test and homogeneity of Kappas were calculated. By words found that 55.1%, 77.5%, 32.2% and 25.1% of mothers of underweight, normal, overweight, and obese children had an adequate perception. By images found that 76.4%, 92.9%, 73.0%, and 89% of mothers of underweight, normal, overweight, and obese children had an adequate perception. Sensitivity, specificity, and Kappa values for the words were 28.4%, 22.5% and 0.442 (p=0.000); for the images were 81.6%, 23.6% and 0.043 (p=0.001). A small proportion of mothers of overweightobese children had adequate perception by words . The images had higher sensitivity. There are various levels of homogeneity across the States.