Prakash Ranjan Mondal

Spectrum of MTHFR gene SNPs C677T and A1298C: a study among 23 population groups of India.

Elevated homocysteine is a risk factor for many complex disorders. The role of methylenetetrahydrofolate reductase (MTHFR) gene in methylation of homocysteine makes it one of the most important candidate genes for these disorders. Considering the heterogeneity in its distribution in world populations, we screened MTHFR C677T and A1298C single nucleotide polymorphisms in a total of 23 Indian caste, tribal and religious population groups from five geographical regions of India and belonging to four major linguistic groups. The frequencies of MTHFR 677T and 1298C alleles were found to be 10.08 and 20.66%, respectively. MTHFR homozygous genotype 677TT was absent in eight population groups and homozygous 1298CC was absent in two population groups. 677T allele was found to be highest among north Indian populations with Indo-European tongue and 1298C was high among Dravidian-speaking tribes of east India and south India. The less common mutant haplotype 677T-1298C was observed among seven population groups and overall the frequency of this haplotype was 0.008, which is similar to that of African populations. cis configuration of 677T and 1298C was 0.94%. However, we could not find any individual with four mutant alleles which supports the earlier observation that presence of more than two mutant alleles may decrease the viability of foetus and possibly be a selective disadvantage in the population.

Glucose-6-Phosphate Dehydrogenase Deficiency and Sickle Cell Hemoglobin among the Warli Tribe of Dadra and Nagar Haveli

Abstract Anthropologists have always used Glucose-6-Phosphate dehydrogenase (G6PD) deficiency and sickle cell haemoglobin to trace human evolution and migratory histories of populations. The present study deals with the screening of these markers among the Warli population of Dadra and Nagar Haveli. The study aims to enhance the knowledge in the realm of population genetics vis-à-vis these two loci. Of the 79 males studied, 8 (10.1%) were found to be G6PD deficient. Regarding the Sickle cell haemoglobin, the present sample showed no HbSS. However Heterozygotes (HbAS) constitute (12.7%) of the persons studied for the purpose. The population is in Hardy Weinberg equilibrium with respect to both selected loci.

Beneficial role of D allele in controlling ACE levels: a study among Brahmins of north India

India being a country with vast diversity is expected to have different dietary and life style patterns which in turn may lead to population-specific environmental risk factors. Further, the interaction of these risk factors with the genetic makeup of population makes it either susceptible or resistant to cardiovascular disease. One such candidate gene is angiotensin converting enzyme (ACE) for various cardiovascular mechanisms. ACE is the key enzyme of the renin angiotensin aldosterone system pathway which maintains homeostasis blood pressure in the body and any variation in the levels is reported to be associated with various complex diseases. The DD genotype is found to increase ACE levels, which is associated with cardiovascular diseases and decrease in ACE levels are associated with kidney diseases. The aim of this study was to understand the distribution of ACE I/D polymorphism and ACE levels among Brahmins of National Capital Region (NCR) north India, with respect to age and sex ratio distribution. In this study, 136 subjects of which 50 males and 86 females, who were unrelated up to first cousin, aged 25 to70 years were studied. ACE gene was found to be polymorphic with high frequency of heterozygote (ID) followed by II and DD genotypes. The studied population was found to be in Hardy–Weinberg equilibrium with respect to ACE I/D polymorphism (P = 0.55). I allele frequency was found to be higher (0.560) than the D allele (0.44). The median level of ACE was found to be 65.96 ng/mL (48.12–86.24) which is towards lower side of the normal range. ACE levels were found to be increased among individual having either of the homozygotes that is II or DD and higher frequency of heterozygote (ID) is indicative of advantage in the population by maintaining lower ACE levels. The limitation of the present study is low sample size, however, the merit is that the subjects belonged to a Mendalian population with a common gene pool.

Differential distribution and association of FTO rs9939609 gene polymorphism with obesity: A cross-sectional study among two tribal populations of India with East-Asian ancestry

The fat mass and obesity associated (FTO) rs9939609 gene polymorphism is most widely studied in terms of obesity in various populations. Recently, the prevalence of obesity has been reported to be very high among the North-Eastern State of India. The major aim of the present study is to understand the extent of FTO rs9939609 gene polymorphism and its association with obesity among the two North-East Indian tribal populations with similar East Asian ancestry. Somatometric data and fasting blood sample were collected from 521 tribal individuals (258 Liangmai and 263 Mizo) of Manipur after obtaining written informed consent. Genotyping of FTO rs9939609 single nucleotide polymorphism (SNP) was done using restriction fragment length polymorphism method for PCR-amplified fragments. Both the presently studied populations were not following Hardy-Weinberg law. The prevalence of obesity and minor allele frequency of FTO rs9939609 polymorphism was found to be significantly higher among the Mizo tribe compared to that of Liangmai. The selected polymorphism was found to be significantly associated with obesity (BMI) only among the Liangmai tribe (Odds ratio-3.0; 95% CI-1.4, 6.4; p-0.003), after adjusting for age and occupation. Age-cohort wise distribution and absolute fitness analysis indicated the lower fitness of minor allele in the higher age group among the Liangmai tribe. To the best of the authors knowledge this is the first study, associating FTO rs9939609 gene polymorphism and obesity in the North-eastern Indian tribal populations with East-Asian ancestry. This study revealed the FTO rs9939609 polymorphism is observed to be associated with obesity only among the Liangmai tribe not among the Mizo tribe. The differential distribution and association observed in the two selected tribes, inhabited in a similar geographical region, could be attributed to differences in their migratory histories in terms of both route and time of settlement.

The genomic similarities with linguistic difference: a study among the Oraon and Munda tribes of the Ranchi district, Jharkhand, India.

AIMS The present study was conducted on two tribal communities, the Oraon and Munda, inhabiting the Ranchi district of Jharkhand state, India. The study was designed to elucidate genetic similarity, if any, shared between these tribes as they belong to the common Proto-Australoid stock but bear different linguistic affiliations. For this, a total of 98 intravenous blood samples (48 Oraon and 50 Munda) were collected from unrelated individuals of either sex up to first cousins, with their prior informed written consent. The DNA was extracted and studied for a total of 20 autosomal markers, including 7 Alu Indels, 3 DRD2 TaqI sites, 3 β-globin sites, and 7 restriction site polymorphisms. RESULTS All the 20 studied molecular markers were found to be polymorphic in both the tribal population groups and showed similarities with respect to allele frequencies, with a low coefficient of gene differentiation (G(ST)) value. Moreover, sharing and distribution patterns of haplotypes of the β-globin gene cluster suggest that the Oraon and Munda share a common ancestry. However, small differences between them with reference to the linkage disequilibrium (LD) pattern indicate that the Munda might have emerged as a result of admixture between Proto-Australoids and Austro-Asiatic-speaking Mongoloids as supported by the principal co-ordinate analysis, wherein the Munda are closely placed with the Dravidian-speaking Proto-Australoid tribes of India. CONCLUSION A common genetic substratum (Proto-Australoid stock) of the Oraon and Munda was evident in the present study, although these tribes are distinct linguistically.

Type 2 diabetes and FTO rs9939609 gene polymorphism: a study among the two tribal population groups of Manipur, North East India

Diabetes is one of the most underrated epidemic worldwide, and its prevalence has increased rapidly in developing nations like India. It has increased not only in the general population per se, but even among the indigenous tribal populations also. Several candidate genes have been associated with type 2 diabetes, and the association of type 2 diabetes and FTO rs9939609 gene polymorphism is a matter of debate. The present study aims to understand the prevalence of type-2 diabetes and its association with FTO rs9939609 gene polymorphism, among the Naga and Mizo tribe of Manipur, North East India. Demographic, somatometric variables and blood samples from 521 individuals were collected and FTO rs9939609 variant was screened. The prevalence of type 2 diabetes/impaired fasting glucose was found to be 10.1 and 43.73% among the Liangmai and Mizo tribe, respectively. The FTO variant showed an increased risk for impaired fasting glucose (OR 1.25; CI 0.38–4.1) among the Liangmai tribe, but among Mizo tribe, it showed an increased risk for type 2 diabetes (OR 1.34; CI 0.73–2.4), albeit with no statistical significances. This suggests that there seems to be diverse effect of FTO rs9939609 A allele in the two tribes, i.e., disadvantageous effect among Liangmai tribe and an adaptive effect among Mizo tribe.

Biological and Social Determinants of Fertility Behaviour among the Jat Women of Haryana State, India

Fertility is a way through which human beings biologically replace themselves in order to continue their existence on earth. The present paper therefore attempts to study the factors affecting fertility among the Jat women of Haryana state. A household survey was conducted in 15 villages of Palwal district in which the concentration of Jats was found to be highest and 1014 ever married women were interviewed. Age at marriage, present age, education status, family type, and preference for male child were the most important factors that affected fertility in the studied population. Age at menarche, age at first conception, occupation status, use of birth control measures, and household per capita annual income did not affect the fertility in the studied population.

Dopamine D2 receptor and ankyrin repeat and kinase domain containing 1 genes among the two linguistically distinct tribal populations of Ranchi district, Jharkhand, India.

In the recent years, haplotype studies have emerged as a critical tool for studying the human migratory patterns. Dopamine D2 receptor (DRD2) and Ankyrin Repeat and Kinase Domain Containing 1 (ANKK1) genes, which also bear specific clinical implications in various neuropsychiatric and behavioural/addictive disorders, are significant nuclear DNA markers for studying human genome diversity. The present study was conducted in order to understand the distribution pattern of the three DRD2 and ANKK1 TaqI sites and also the frequencies of their haplotypes among Oraons (n = 48) and Mundas (n = 50)--the two linguistically distinct tribal population groups of Jharkhand. The phylogenetic inference was drawn through the statistical comparisons of the present DRD2 and ANKK1 TaqI site data with the available data from population groups belonging to other parts of India and also rest of the world (ALFRED Database). All the three TaqI sites were found to be polymorphic among Oraons and Mundas with relatively high average heterozygosities. Oraons exhibited a comparatively higher frequency of the ancestral B2D2A1 haplotype (0.356) than the Mundas (0.193). Significant and higher linkage disequilibrium (LD) values between all three sites were observed among Mundas which is indicative of admixture, whereas Oraons exhibited non significant and low LD values. The presence of ancestral haplotype B2D2A1 in higher frequency and lower and non-significant LD among Oraons suggest that they might be the older inhabitants in the region though the major limitation of the study is small sample size which might have introduced bias in the accuracy of the calculated pairwise LD for the three polymorphic sites.

Haptoglobin polymorphism among fourteen populations of India.

Haptoglobin (HP) is a serum protein that has the capability of binding the extracorpuscular haemoglobin released during haemolysis. It plays an important role in protection of haemolytic disease by reducing the oxidative and peroxidative potential at free haemoglobin. The present study was aimed to determine the prevalence of HP polymorphism among different Indian populations, anthropologically belonging to diverse ethnicity. The polymorphism was screened among 642 unrelated individuals belonging to 14 population groups of India including both tribal and non-tribal caste groups from different geographical regions of India with distinct linguistic affiliations. An attempt is also made to understand the distribution of HP polymorphism among the studied populations. The result reveals the HP gene to be polymorphic in all the studied populations. Except the two tribal populations (Thotis of Andhra Pradesh and Patelias of Rajasthan) and one caste population (Rajput of Himachal Pradesh), all the studied populations are found to obey the Hardy-Weinberg equilibrium. The significance of the present study is elucidated with the prevalence of high mutant HP*2 allele frequency in India. Selection could be one of the most plausible explanations for this high HP frequency because of its uniformly high occurrence among all the studied populations.