Northeast India, the only region which currently forms a land bridge between the Indian subcontinent and Southeast Asia, has been proposed as an important corridor for the initial peopling of East Asia. Given that the Austro-Asiatic linguistic family is considered to be the oldest and spoken by certain tribes in India, Northeast India and entire Southeast Asia, we expect that populations of this family from Northeast India should provide the signatures of genetic link between Indian and Southeast Asian populations. In order to test this hypothesis, we analyzed mtDNA and Y-Chromosome SNP and STR data of the eight groups of the Austro-Asiatic Khasi from Northeast India and the neighboring Garo and compared with that of other relevant Asian populations. The results suggest that the Austro-Asiatic Khasi tribes of Northeast India represent a genetic continuity between the populations of South and Southeast Asia, thereby advocating that northeast India could have been a major corridor for the movement of populations from India to East/Southeast Asia.

BACKGROUND In this study, recurrent miscarriages (RMs) are defined as loss of two or more clinically detectable pregnancies before 20 weeks of gestation. HLA has been thought to play a role in RM. However, the results of earlier studies on the role of different human leucocyte antigen (HLA) genes were conflicting and inconclusive. In the present study, we investigate HLA genes (HLA-DRA, HLA-DRB1, HLA-DQA1 and HLA-DQB1) in RM couples with unknown etiology and normal couples. METHODS Blood samples from 143 RM couples and 150 control couples were analyzed, firstly to validate previously reported association studies and secondly to explore whether any novel alleles or haplotypes specific to Indian populations can be observed to be associated with RM. HLA typing was carried out by DNA sequencing. RESULTS Results suggest an association of the DQB1*03:03:02 allele with RM (odd ratio = 2.66; p(c) = 0.02; confidence interval = 1.47-4.84). Haplotypes of the DQA1 and DQB1 risk alleles also showed a significant association with RM, albeit not after Bonferroni correction for multiple comparisons. CONCLUSIONS HLA-DQB1 appears to have a strong involvement in the manifestation of RM in this population from South India. The current genetic analysis of RM and control couples not only highlights the genes exhibiting a strong etiological role but also reflects the protective nature of some HLA genes against RM. Nevertheless, most of these alleles/haplotypes were not those that are implicated in RM in other ethnic backgrounds, and hence require further validation in other populations of India, from different ethnic and/or geographic backgrounds.

BackgroundWe attempt to ascertain if the 3 linked single nucleotide polymorphisms (SNPs) of the Progesterone Receptor (PR) gene (exon 1: G 1031 C; S344T, exon 4: G 1978 T; L660V and exon 5: C 2310 T; H770H) and the PROGINS insertion in the intron G, between exons 7 and 8, are associated with Recurrent Spontaneous Abortion (RSA) in the Indian population.Methodology/Principal FindingsA total of 143 women with RSA and 150 controls were sequenced for all the 8 exons looking for the above 3 linked SNPs of the PR gene earlier implicated in the RSA, as well as for any new SNPs that may be possibly found in the Indian population. PROGINS insertion was screened by electrophoresis. We did not find any new mutations, not observed earlier, in our population. Further, we did not find significant role of the *2 allele (representing the mutant allele at the three SNP loci) or the T2 allele (PROGINS insertion) in the manifestation of RSA. We also did not find an LD pattern between each of the 3 SNPs and the PROGINS insertion.Conclusions/SignificanceThe results suggest that the PR gene mutations may not play any exclusive role in the manifestation of RSA, and instead, given significantly higher frequency of the *2 allele among the normal women, we surmise if it does not really confer a protective role among the Indian populations, albeit further studies are required in the heterogeneous populations of this region before making any conclusive statement.

We report single nucleotide polymorphisms (SNPs) at the four sites in ADH2 and ADH3 genes among the 28 populations from southern parts of Andhra Pradesh, India. A total of 1048 individuals belonging to 28 endogamous populations distributed in the contiguous areas of the 6 southernmost districts of Andhra Pradesh were enrolled for the present study. Genotyping involved PCR and sequencing. We sequenced exon 3 and 9 of ADH2 and exon 8 of ADH3, besides the ADH2 3'UTR-rs17033 (72 bases down stream of ADH2 Arg369Cys). The two sites of ADH2 (Arg47His and Arg369Cys) are found to be completely monomorphic showing only Arg47 and 369Arg (ADH2*1 allele), the remaining two sites were polymorphic. None of the 28 populations of this study deviated significantly from Hardy Weinberg Equilibrium proportions. The allele frequencies do not show any clear trend across socioeconomic groups. The degree of heterogeneity in the genotype frequencies among the hierarchical groups is significant for Ile349Val (df = 12; χ 2 = 22.050) and not for the 3'UTR rs17033 (df = 6; χ 2 = 9.765). The haplotype distribution among the hierarchical groups is found to be highly homogeneous and statistically nonsignificant (χ 2 = 0.248, df = 18). Linkage disequilibrium does not exist between the two-polymorhic loci. The results were interpreted in the light of cultural patterns of the Indian hierarchical society.

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