Genomic diversities and affinities among eight endogamous groups of Haryana (India): A study on insertion/deletion polymorphisms

CYP19 gene rs2414096 variant and differential genetic risk of polycystic ovary syndrome: a systematic review and meta-analysis

Previously, many studies investigated the association between CYP19 rs2414096(G > A) and susceptibility to develop PCOS. However, results had been inconsistent. Therefore, our systematic review and meta-analysis aimed to identify the association between CYP19 rs2414096 and PCOS risk. Methods: A systematic literature search was done from database PubMed, Google Scholar, Science Direct, and Cochrane Library up to July 15 2020 and statistical analysis was performed by RevMan5.3. Results: A total of seven studies comprised of 1414 PCOS cases and 1276 controls were included in the current meta-analysis. The pooled analysis showed that overall, there is a significant association between CYP19 rs2414096(G > A) and risk of PCOS (OR = 0.74, 95% CI= 0.62-0.88, p = .0008). In dominant model, GG + AG vs GG and recessive genetic model AA vs AG + GG found a significant association (OR = 1.60,95% CI = 1.10-2.31, p = .01; OR = 0.65,95% CI = 0.45-0.93, p = .02) respectively which indicates that GG phenotype might be risk factor for PCOS development. In stratified subgroup analysis, there was significant association between CYP19 rs2414096 polymorphism and PCOS risk for non-Indian population only while no association was found with Indian population. Conclusion: Present meta-analysis studies indicate that CYP19 rs2414096 is associated with PCOS risk and important in pathogenesis of PCOS for many populations but for Indian population more studies are required as Indian population comprises of various subpopulations genetically isolated since long.

Genetic dissection of five ethnic groups from Punjab, North-West India-A study based on Autosomal Markers

The present study assessed the applicability of Alu insertion elements and Single Nucleotide Polymorphisms (SNPs) in forensic identification and estimated the extent of genetic variation in five major ethnic groups of Punjab, North-West India. A total of 1012 unrelated samples belonging to Banias, Brahmins, Jat Sikhs, Khatris and Scheduled Castes were genotyped for four Alu elements (ACE, APO, PLAT, D1) and six Single Nucleotide Polymorphisms [ESR (PvuII), LPL (PvuII), HTR2A (MspI), DRD2 Taq1A, Taq1B, Taq1D]. Allele frequencies observed heterozygosity and forensic efficacy parameters were determined. The data on the genetic affinity of the studied populations among themselves and with other populations of India was also analysed using a Neighbor-Joining tree and multidimensional scaling plot respectively. All the 10 loci were polymorphic and their average observed heterozygosity ranged from 0.3872 (Banias) to 0.4311 (Scheduled Castes). Allele frequency variation at the 9 out of 10 loci led to statistically significant pairwise differences among the five study population groups. The result from AMOVA, Structure analysis, and Phylogenetic tree suggests that these populations are homogenous. In the multidimensional scaling plot, the present study populations formed a compact cluster clearly separated from other populations, suggesting a unique genetic identity of the Punjab populations as a whole. All these observations suggest that either a recent common origin of these populations or extensive gene flow across the populations that dissolve the original genetic differences. The data generated in this study will be useful for forensic genetics, molecular anthropological and demographic studies.

Unity in diversity: an overview of the genomic anthropology of India

CONTEXT

India is considered a treasure for geneticists and evolutionary biologists due to its vast human diversity, consisting of more than 4500 anthropologically well-defined populations (castes, tribes and religious groups). Each population differs in terms of endogamy, language, culture, physical features, geographic and climatic position and genetic architecture. These factors contributed to India-specific genetic variations which may be responsible for various common diseases in India and its migratory populations. As a result, interpretations of the origins and affinities of Indian populations as well as health and disease conditions require complex and sophisticated genetic analysis. Evidence of ancient human dispersals and settlements is preserved in the genome of Indian inhabitants and this has been extensively analysed in conventional and genomic analyses.

OBJECTIVE AND METHODS

Using genomic analyses of STRs and Alu on a set of populations, this study estimates the level and extent of genetic variation and its implications.

RESULTS

The results show that Indian populations have a higher level of unique genetic diversity which is structured by many social processes and geographical attributes of the country.

CONCLUSION

This overview highlights the need to study the anthropological structure and evolutionary history of Indian populations while designing genomic and epigenomic investigations.

Genomic diversity and affinities in population groups of North West India: an analysis of Alu insertion and a single nucleotide polymorphism

The North West region of India is extremely important to understand the peopling of India, as it acted as a corridor to the foreign invaders from Eurasia and Central Asia. A series of these invasions along with multiple migrations led to intermixture of variable populations, strongly contributing to genetic variations. The present investigation was designed to explore the genetic diversities and affinities among the five major ethnic groups from North West India; Brahmin, Jat Sikh, Bania, Rajput and Gujjar. A total of 327 individuals of the abovementioned ethnic groups were analyzed for 4 Alu insertion marker loci (ACE, PV92, APO and D1) and a Single Nucleotide Polymorphism (SNP) rs2234693 in the intronic region of the ESR1 gene. Statistical analysis was performed to interpret the genetic structure and diversity of the population groups. Genotypes for ACE, APO, ESR1 and PV92 loci were found to be in Hardy-Weinberg equilibrium in all the ethnic groups, while significant departures were observed at the D1 locus in every investigated population after Bonferroni's correction. The average heterozygosity for all the loci in these ethnic groups was fairly substantial ranging from 0.3927 ± 0.1877 to 0.4333 ± 0.1416. Inbreeding coefficient indicated an overall 10% decrease in heterozygosity in these North West Indian populations. The gene differentiation among the populations was observed to be of the order of 0.013. Genetic distance estimates revealed that Gujjars were close to Banias and Jat Sikhs were close to Rajputs. Overall the study favored the recent division of the populations of North West India into largely endogamous groups. It was observed that the populations of North West India represent a more or less homogenous genetic entity, owing to their common ancestral history as well as geographical proximity.