The phylogeography of Y-chromosome haplogroup h1a1a-m82 reveals the likely Indian origin of the European Romani populations

The genetic footprint of the European Roma diaspora: evidence from the Balkans to the Iberian Peninsula

The Roma people have a complex demographic history shaped by their recent dispersal from a South Asian origin into Europe, accompanied by continuous population bottlenecks and gene flow. After settling in the Balkans around 1,000 years ago, the Roma gradually dispersed across Europe, and approximately 500 years ago, they established in the Iberian Peninsula what is now one of the largest Roma populations in Western Europe. Focusing specifically on the Iberian Roma, we conducted the most comprehensive genome-wide analysis of European Roma populations to date. Using allele frequency and haplotype-based methods, we analysed 181 individuals to investigate their genetic diversity, social dynamics, and migration histories at both continental and local scales. Our findings demonstrate significant gene flow from populations encountered during the Roma's dispersal and confirm their South Asian origins. We show that, between the 14th and 19th centuries, the Roma spread westward from the Balkans in various waves, with multiple admixture events. Furthermore, our findings refute previous hypotheses of a North African dispersal route into Iberia and genetic connections to Jewish populations. The Iberian Roma exhibit ten times greater genetic differentiation compared to non-Roma Iberians, indicating significant regional substructure. Additionally, we provide the first genetic evidence of assortative mating within Roma groups, highlighting distinct mating patterns and suggesting a gradual shift towards increased integration with non-Roma individuals. This study significantly enhances our understanding of how demographic history and complex genetic structure have shaped the genetic diversity of Roma populations, while also highlighting the influence of their evolving social dynamics.

Increased prevalence of the COVID-19 associated Neanderthal mutations in the Central European Roma population

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and subsequent COVID-19 has spread world-wide and become pandemic with about 7 million deaths reported so far. Interethnic variability of the disease has been described, but a significant part of the differences remain unexplained and may be attributable to genetic factors.

AIM

To analyse genetic factors potentially influencing COVID-19 susceptibility and severity in European Roma minority.

SUBJECTS AND METHODS

Two genetic determinants, within OAS-1 (2-prime,5-prime-oligoadenylate synthetase 1, a key protein in the defence against viral infection; it activates RNases that degrade viral RNAs; rs4767027 has been analysed) and LZTFL1 (leucine zipper transcription factor-like 1, expressed in the lung respiratory epithelium; rs35044562 has been analysed) genes were screened in a population-sample of Czech Roma (N = 302) and majority population (N = 2,559).

RESULTS

For both polymorphisms, Roma subjects were more likely carriers of at least one risky allele for both rs4767027-C (p < 0.001) and rs35044562-G (p < 0.00001) polymorphism. There were only 5.3% Roma subjects without at least one risky allele in comparison with 10.1% in the majority population (p < 0.01).

CONCLUSIONS

It is possible that different genetic background plays an important role in increased prevalence of COVID-19 in the Roma minority.

Complete mitochondrial DNA sequence tries to settle hitherto putative history of Kayastha population of India

OBJECTIVES

Indian caste system is unique as it has an inimitable type of class system where the social ordering is done based on birth. Within the caste system, there is a distinct endogamous population known as the Kayastha, who have had inconclusive stratification records due to unidentified historical records.

METHODS

To gain a more inclusive view on the history and genetic affinities of Kayastha people, complete mitochondrial genomes from 15 individuals of a Kayastha population from North-western India have been sequenced.

RESULTS

Interestingly, three novel sub-clades (U2b2a, M3d2, and M33a3b) have been identified that represent unique Kayastha motifs.

CONCLUSION

The haplotype-based analysis suggests that the Kayastha population shares genetic affinities with the Indo-European and Sino-Tibetan populations found in the trans-Himalayan region. The F_ST based population comparison and the MDS plot indicates that Kayastha people have close maternal genetic affinity with the available genetic database of Brahmins, Kashmiris, and Tharus. The maternal genetic lineages among Kayastha population shows deep in situ origin that emerged much before settled life developed on this sub-continent. Both mtDNA and Y-chromosome markers, trace the genetic lineages of Kayastha population with Tharus, who regard themselves Kshatriya, corroborated by the oral history of the Kayasthas for their Kshatriya affiliation. It also validates genetic heritage of earliest settlers of India in both indigenous tribal and caste populations.

Founder lineages in the Iberian Roma mitogenomes recapitulate the Roma diaspora and show the effects of demographic bottlenecks

The Roma are the largest ethnic minority in Europe. With a Northwestern Indian origin around ~ 1.5 kya, they travelled throughout West Asia until their arrival in Europe around the eleventh century CE. Their diaspora through Europe is characterized by population bottlenecks and founder events which have contributed to their present day genetic and cultural diversity. In our study, we focus on the effects of founder effects in the mitochondrial DNA (mtDNA) pool of Iberian Roma by producing and analyzing 144 novel whole mtDNA sequences of Iberian Roma. Over 60% of their mtDNA pool is composed by founder lineages of South Asian origin or acquired by gene flow during their diaspora in the Middle East or locally in Europe in Europe. The TMRCA of these lineages predates the historical record of the Roma arrival in Spain. The abundance of founder lineages is in contrast with ~ 0.7% of autochthonous founder lineages present in the non-Roma Iberian population. Within those founder lineages, we found a substantial amount of South Asian M5a1b1a1 haplotypes and high frequencies of West Eurasian founder lineages (U3b1c, J2b1c, J1c1b, J1b3a, H88, among others), which we characterized phylogenetically and put in phylogeographical context. Besides, we found no evidence of genetic substructure of Roma within the Iberian Peninsula. These results show the magnitude of founder effects in the Iberian Roma and further explain the Roma history and genetic diversity from a matrilineal point of view.

Biodiversity of Mycobacterium tuberculosis in Bulgaria Related to Human Migrations or Ecological Adaptation

Bulgaria is among the 18 high-priority countries of the WHO European Region with high rates of tuberculosis. The causative agent of tuberculosis is thought to have emerged in Africa 70,000 years ago, or during the Neolithic age, and colonized the world through human migrations. The established main lineages of tuberculosis correlate highly with geography. The goal of our study was to investigate the biodiversity of Mycobacteriumtuberculosis in Bulgaria in association with human migration history during the last 10 centuries. We analyzed spoligotypes and MIRU-VNTR genotyping data of 655 drug-sensitive and 385 multidrug-resistant M. tuberculosis strains collected in Bulgaria from 2008 to 2018. We assigned the genotype of all isolates using SITVITWEB and MIRU-VNTRplus databases and software. We investigated the major well-documented historical events of immigration to Bulgaria that occurred during the last millennium. Genetic profiles demonstrated that, with the exceptions of 3 strains of Mycobacterium bovis and 18 strains of Lineage 2 (W/Beijing spoligotype), only Lineage 4 (Euro-American) was widely diffused in Bulgaria. Analysis of well-documented immigrations of Roma from the Indian subcontinent during the 10th to the 12th centuries, Turkic peoples from Central Asia in the medieval centuries, and more recently Armenians, Russians, and Africans in the 20th century influenced the biodiversity of M. tuberculosis in Bulgaria but only with genotypes of sublineages within the L4. We hypothesize that these sublineages were more virulent, or that ecological adaptation of imported M. tuberculosis genotypes was the main driver contributing to the current genetic biodiversity of M. tuberculosis in Bulgaria. We also hypothesize that some yet unknown local environmental factors may have been decisive in the success of imported genotypes. The ecological factors leading to local genetic biodiversity in M. tuberculosis are multifactorial and have not yet been fully clarified. The coevolution of long-lasting pathogen hosts should be studied, taking into account environmental and ecological changes.

Paternal genetic structure of the Bosnian-Herzegovinian Roma: A Y-chromosomal STR study

OBJECTIVES

Studies indicate the complex nature of the genetic structure of the European Roma which has been shaped by different effects of their demographic history, while preserving their ancestral Indian origin. The primary aims of this study were to present for the first time the paternal profiles of the Roma from Bosnia and Herzegovina based on the data from Y-chromosome STR loci, identify the components of non-Roma paternal gene flow into the Roma, and evaluate the genetic relationships with other European Roma populations.

MATERIALS AND METHODS

In this study, 110 DNA samples of unrelated males from Roma populations residing in different regions of Bosnia and Herzegovina were genotyped using the 23 Y-STR loci included in the PowerPlex Y23 system.

RESULTS

The analysis of the genetic structure of the Bosnian-Herzegovinian Roma revealed intra-country population substructuring and indicated differing genetic affinities between the Bosnian-Herzegovinian Roma and other European Roma populations. The paternal genetic structure of the Bosnian-Herzegovinian Roma has two components: an ancestral component represented by haplogroup H1a1a-M82, and European component presented by haplogroups I1-M253, I2a1a2b-L621, J2a1a-L26, J2a1a1a2b2a3~Z7671, J2b2a-M241, G2a2b2a1a1b-L497, and E1b1b-M215.

CONCLUSION

Genetic relations between the Bosnian-Herzegovinian Roma and other European Roma are shaped by different influences on their demographic history. The data suggest that the paternal gene pool of the Roma from Bosnia and Herzegovina might be a consequence of an early separation of the proto-Roma population and the later gene flow as well as factors of the isolation that accompany the Roma populations in some Bosnian-Herzegovinian regions.

Using Y-chromosome capture enrichment to resolve haplogroup H2 shows new evidence for a two-path Neolithic expansion to Western Europe

Uniparentally-inherited markers on mitochondrial DNA (mtDNA) and the non-recombining regions of the Y chromosome (NRY), have been used for the past 30 years to investigate the history of humans from a maternal and paternal perspective. Researchers have preferred mtDNA due to its abundance in the cells, and comparatively high substitution rate. Conversely, the NRY is less susceptible to back mutations and saturation, and is potentially more informative than mtDNA owing to its longer sequence length. However, due to comparatively poor NRY coverage via shotgun sequencing, and the relatively low and biased representation of Y-chromosome variants on capture assays such as the 1240 k, ancient DNA studies often fail to utilize the unique perspective that the NRY can yield. Here we introduce a new DNA enrichment assay, coined YMCA (Y-mappable capture assay), that targets the "mappable" regions of the NRY. We show that compared to low-coverage shotgun sequencing and 1240 k capture, YMCA significantly improves the mean coverage and number of sites covered on the NRY, increasing the number of Y-haplogroup informative SNPs, and allowing for the identification of previously undiscovered variants. To illustrate the power of YMCA, we show that the analysis of ancient Y-chromosome lineages can help to resolve Y-chromosomal haplogroups. As a case study, we focus on H2, a haplogroup associated with a critical event in European human history: the Neolithic transition. By disentangling the evolutionary history of this haplogroup, we further elucidate the two separate paths by which early farmers expanded from Anatolia and the Near East to western Europe.

Recent Common Origin, Reduced Population Size, and Marked Admixture Have Shaped European Roma Genomes

The Roma Diaspora-traditionally known as Gypsies-remains among the least explored population migratory events in historical times. It involved the migration of Roma ancestors out-of-India through the plateaus of Western Asia ultimately reaching Europe. The demographic effects of the Diaspora-bottlenecks, endogamy, and gene flow-might have left marked molecular traces in the Roma genomes. Here, we analyze the whole-genome sequence of 46 Roma individuals pertaining to four migrant groups in six European countries. Our analyses revealed a strong, early founder effect followed by a drastic reduction of ∼44% in effective population size. The Roma common ancestors split from the Punjabi population, from Northwest India, some generations before the Diaspora started, <2,000 years ago. The initial bottleneck and subsequent endogamy are revealed by the occurrence of extensive runs of homozygosity and identity-by-descent segments in all Roma populations. Furthermore, we provide evidence of gene flow from Armenian and Anatolian groups in present-day Roma, although the primary contribution to Roma gene pool comes from non-Roma Europeans, which accounts for >50% of their genomes. The linguistic and historical differentiation of Roma in migrant groups is confirmed by the differential proportion, but not a differential source, of European admixture in the Roma groups, which shows a westward cline. In the present study, we found that despite the strong admixture Roma had in their diaspora, the signature of the initial bottleneck and the subsequent endogamy is still present in Roma genomes.

Partial-AZFc deletions in Chilean men with primary spermatogenic impairment: gene dosage and Y-chromosome haplogroups

PURPOSE

To investigate the association of partial-AZFc deletions in Chilean men with primary spermatogenic failure and their testicular histopathological phenotypes, analyzing the contribution of DAZ dosage, CDY1 copies, and Y-chromosome haplogroups.

SUBJECTS AND METHODS

We studied 479 Chilean men: 334 infertile patients with histological examination (233 cases with spermatogenic defects and 101 normal spermatogenesis, obstructive controls, OC), and 145 normozoospermic controls (NC). AZFc subdeletions were detected by single-tagged sequences and single nucleotide variants analysis. DAZ-copy number was quantified by real-time qPCR. Y-chromosome haplogroups (Y-hg) were hierarchically genotyped through 16 biallelic-markers.

RESULTS

The prevalence of AZFc-partial deletions was increased in cases (6%) compared with NC (1.4%) (P = 0.035). There was no difference between 143 Sertoli-cell only syndrome, 35 maturation arrest, or 35 mix atrophy patients and controls. However, gr/gr deletions were more frequent in 16 subjects with hypospermatogenesis compared with NC (P = 0.003) and OC (P = 0.013). Y-hg R was the most prevalent (~ 50%), but decreased among gr/gr deletions (21%, P = 0.03). The prevalence of Y-hg M increased in cases versus controls, both in total and non-deleted men (3.9 and 3.7% versus 0.4%, P = 0.009 and P = 0.016, respectively). Among gr/gr deletions, Y-hg H increased compared with non-deleted men (14.3% versus 0.4%, P = 0.0047).

CONCLUSION

Partial-AZFc deletions in a Chilean admixed population are associated with secretory azo/oligozoospermia and might have a role in the development of hypospermatogenesis. Low represented haplogroups, Y-hg M and Y-hg H, show an association with the occurrence of spermatogenic failure and gr/gr deletions respectively; however, additional studies are required.

The shaping of immunological responses through natural selection after the Roma Diaspora

The Roma people are the largest transnational ethnic minority in Europe and can be considered the last human migration of South Asian origin into the continent. They left Northwest India approximately 1,000 years ago, reaching the Balkan Peninsula around the twelfth century and Romania in the fourteenth century. Here, we analyze whole-genome sequencing data of 40 Roma and 40 non-Roma individuals from Romania. We performed a genome-wide scan of selection comparing Roma, their local host population, and a Northwestern Indian population, to identify the selective pressures faced by the Roma mainly after they settled in Europe. We identify under recent selection several pathways implicated in immune responses, among them cellular metabolism pathways known to be rewired after immune stimulation. We validated the interaction between PIK3-mTOR-HIF-1α and cytokine response influenced by bacterial and fungal infections. Our results point to a significant role of these pathways for host defense against the most prevalent pathogens in Europe during the last millennium.

Sex-biased patterns shaped the genetic history of Roma

The Roma population is a European ethnic minority characterized by recent and multiple dispersals and founder effects. After their origin in South Asia around 1,500 years ago, they migrated West. In Europe, they diverged into ethnolinguistically distinct migrant groups that spread across the continent. Previous genetic studies based on genome-wide data and uniparental markers detected Roma founder events and West-Eurasian gene flow. However, to the best of our knowledge, it has not been assessed whether these demographic processes have equally affected both sexes in the population. The present study uses the largest and most comprehensive dataset of complete mitochondrial and Y chromosome Roma sequences to unravel the sex-biased patterns that have shaped their genetic history. The results show that the Roma maternal genetic pool carries a higher lineage diversity from South Asia, as opposed to a single paternal South Asian lineage. Nonetheless, the European gene flow events mainly occurred through the maternal lineages; however, a signal of this gene flow is also traceable in the paternal lineages. We also detect a higher female migration rate among European Roma groups. Altogether, these results suggest that sociocultural factors influenced the emergence of sex-biased genetic patterns at global and local scales in the Roma population through time.

High frequencies of Non Allelic Homologous Recombination (NAHR) events at the AZF loci and male infertility risk in Indian men

Deletions in the AZoospermia Factor (AZF) regions (spermatogenesis loci) on the human Y chromosome are reported as one of the most common causes of severe testiculopathy and spermatogenic defects leading to male infertility, yet not much data is available for Indian infertile men. Therefore, we screened for AZF region deletions in 973 infertile men consisting of 771 azoospermia, 105 oligozoospermia and 97 oligoteratozoospermia cases, along with 587 fertile normozoospermic men. The deletion screening was carried out using AZF-specific markers: STSs (Sequence Tagged Sites), SNVs (Single Nucleotide Variations), PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) analysis of STS amplicons, DNA sequencing and Southern hybridization techniques. Our study revealed deletion events in a total of 29.4% of infertile Indian men. Of these, non-allelic homologous recombination (NAHR) events accounted for 25.8%, which included 3.5% AZFb deletions, 2.3% AZFbc deletions, 6.9% complete AZFc deletions, and 13.1% partial AZFc deletions. We observed 3.2% AZFa deletions and a rare long AZFabc region deletion in 0.5% azoospermic men. This study illustrates how the ethnicity, endogamy and long-time geographical isolation of Indian populations might have played a major role in the high frequencies of deletion events.

Prevalence of Diabetes Mellitus among Roma Populations-A Systematic Review

Background: The aim of this study was to estimate the prevalence of diabetes mellitus in the Roma population and compare it to the prevalence in the Caucasian population. Methods: Using the words “Roma”, “Gypsies”, “Romani”, and ”traveler” in combination with “diabetes, “metabolic syndrome”, “cardiovascular disease” and “health status” we searched the MEDLINE, Pubmed and Scopus databases for articles in English that focused on the prevalence of diabetes mellitus among Roma populations published until December 2017. Results: Five studies met the inclusion criteria. The results of four of them suggested a higher prevalence of diabetes among Romani compared to Caucasians but none of them reached the standards regarding representative samples and number of cases for a conclusive result. Conclusion: Although some of the existing studies suggest a substantial prevalence of diabetes among Roma populations and even a higher risk of developing diabetes for Roma persons compared to Caucasians, the number of published literature on this topic remains very low and insufficient in design and number of participants to draw any conclusions.

Tau haplotypes support the Asian ancestry of the Roma population settled in the Basque Country

We examined tau haplotype frequencies in two different ethnical groups from the Basque Country (BC): Roma people and residents of European ancestry (general population). In addition, we analyzed the spatial distribution of tau haplotypes in Eurasian populations to explore the genetic affinities of the Romani groups living in Europe in a broader scope. The 17q21.31 genomic region was characterized through the genotyping of two diagnostic single nucleotide polymorphisms, SNPs (rs10514879 and rs199451), which allow the identification of H1 and H2 haplotypes. A significant heterozygous deficit was detected in the Romani for rs10514879. The H2 haplotype frequency proved to be more than twice in the BC general population (0.283) than in the Roma people (0.127). In contrast, H2 frequency proved to be very similar between Basque and Hungarian Romani, and similar to the H2 frequencies found in northwestern India and Pakistan as well. Several statistical analyses unveiled genetic structuring for the MAPT diversity, mirrored in a significant association between geography and genetic distances, with an upward trend of H2 haplotype frequencies from Asia to Europe. Yet, Roma samples did not fit into this general spatial patterning because of their discrepancy between geographical position and H2 frequency. Despite the long spatial coexistence in the Basque region between the residents of European ancestry and the Roma, the latter have preserved their Asian genetic ancestry. Bearing in mind the lack of geographical barriers between both ethnical groups, these findings support the notion that sociocultural mores might promote assortative matings in human populations.

Regional differences in genetic susceptibility to non-alcoholic liver disease in two distinct Indian ethnicities

AIM

To validate the association of variants in PNPLA3 (rs2281135) and TM6SF2 (rs58542926) genes with ultrasound detected non-alcoholic fatty liver disease (NAFLD).

METHODS

A total of 503 individuals with and without fatty infiltration were recruited. Fatty infiltration was confirmed based on ultrasound findings. Anthropometric data and blood samples were collected from the study group. DNA was isolated from peripheral blood, quality and quantity was assessed by gel electrophoresis and spectrophotometer respectively. Genotyping of the variants in PNPLA3 and TM6SF2 genes was carried out by employing taqman probes (C_15875080_10 for PNPLA3 and C_8946351_10 for TM6SF2 SNP) on real time PCR (Stepone-Lifetechnologies). Genotype data was tested for deviations from Hardy-Weinberg equilibrium. χ2 test was used to analyze the statistical significance of the difference in genotype distribution of the studied variants in patients and controls and the strength of association was expressed as odds ratio (95%CI). A two-tailed P value of ≤ 0.05 was considered statistically significant.

RESULTS

The study group comprised of 503 individuals of which 256 had fatty infiltration and 247 without fatty infiltration and thus formed the patient and control groups respectively. As the patient group could be divided in to two distinct ethnicities (ancestral South Indians-ASI and North-East Indians-NEI), further recruitment of control cohort and association analyses was carried out based on ethnicities. Of the 256 with fatty infiltration 93 were ASI and 163 were NEI and of the 247 controls 138 were ASI and 109 were NEI. As expected, there were significant differences in the anthropometric and other clinical data between the control and the patient groups. However significant differences within the ethnicities were also noted. While rs2281135 in PNPLA3 gene was significantly associated (P = 0.03) with higher risk (odds 1.9, 95%CI: 1.5-3.14, P = 0.03) of NAFLD in NEI ethnicity, rs58542926 in TM6SF2 gene was significantly associated with NAFLD with a 2.7 fold higher risk (odds 2.7, 95%CI: 1.37-5.3, P = 0.0004) of the disease. There were significantly higher proportions of individuals with variants in both the genes in the patient group in both ASI (patients - 14/93 and controls - 7/138; P = 0.009) and NEI ethnicities (patients - 17/163 and controls - 7/109; P = 0.01).

CONCLUSION

Although the study identified distinct genetic susceptibility in the two ethnicities, transheterozygosity of the variants suggests higher risk of NAFLD in individuals with both the variants.

A genetic chronology for the Indian Subcontinent points to heavily sex-biased dispersals

BACKGROUND

India is a patchwork of tribal and non-tribal populations that speak many different languages from various language families. Indo-European, spoken across northern and central India, and also in Pakistan and Bangladesh, has been frequently connected to the so-called "Indo-Aryan invasions" from Central Asia ~3.5 ka and the establishment of the caste system, but the extent of immigration at this time remains extremely controversial. South India, on the other hand, is dominated by Dravidian languages. India displays a high level of endogamy due to its strict social boundaries, and high genetic drift as a result of long-term isolation which, together with a very complex history, makes the genetic study of Indian populations challenging.

RESULTS

We have combined a detailed, high-resolution mitogenome analysis with summaries of autosomal data and Y-chromosome lineages to establish a settlement chronology for the Indian Subcontinent. Maternal lineages document the earliest settlement ~55-65 ka (thousand years ago), and major population shifts in the later Pleistocene that explain previous dating discrepancies and neutrality violation. Whilst current genome-wide analyses conflate all dispersals from Southwest and Central Asia, we were able to tease out from the mitogenome data distinct dispersal episodes dating from between the Last Glacial Maximum to the Bronze Age. Moreover, we found an extremely marked sex bias by comparing the different genetic systems.

CONCLUSIONS

Maternal lineages primarily reflect earlier, pre-Holocene processes, and paternal lineages predominantly episodes within the last 10 ka. In particular, genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y-chromosome lineages, a smaller fraction of autosomal genome-wide variation and an even smaller fraction of mitogenomes across a vast swathe of Eurasia between 5 and 3.5 ka.

Complete Genome Sequence of Germline Chromosomally Integrated Human Herpesvirus 6A and Analyses Integration Sites Define a New Human Endogenous Virus with Potential to Reactivate as an Emerging Infection

Human herpesvirus-6A and B (HHV-6A, HHV-6B) have recently defined endogenous genomes, resulting from integration into the germline: chromosomally-integrated “CiHHV-6A/B”. These affect approximately 1.0% of human populations, giving potential for virus gene expression in every cell. We previously showed that CiHHV-6A was more divergent than CiHHV-6B by examining four genes in 44 European CiHHV-6A/B cardiac/haematology patients. There was evidence for gene expression/reactivation, implying functional non-defective genomes. To further define the relationship between HHV-6A and CiHHV-6A we used next-generation sequencing to characterize genomes from three CiHHV-6A cardiac patients. Comparisons to known exogenous HHV-6A showed CiHHV-6A genomes formed a separate clade; including all 85 non-interrupted genes and necessary cis-acting signals for reactivation as infectious virus. Greater single nucleotide polymorphism (SNP) density was defined in 16 genes and the direct repeats (DR) terminal regions. Using these SNPs, deep sequencing analyses demonstrated superinfection with exogenous HHV-6A in two of the CiHHV-6A patients with recurrent cardiac disease. Characterisation of the integration sites in twelve patients identified the human chromosome 17p subtelomere as a prevalent site, which had specific repeat structures and phylogenetically related CiHHV-6A coding sequences indicating common ancestral origins. Overall CiHHV-6A genomes were similar, but distinct from known exogenous HHV-6A virus, and have the capacity to reactivate as emerging virus infections.

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.

Y chromosome haplogroup distribution in Indo-European speaking tribes of Gujarat, western India

The present study was carried out in the Indo-European speaking tribal population groups of Southern Gujarat, India to investigate and reconstruct their paternal population structure and population histories. The role of language, ethnicity and geography in determining the observed pattern of Y haplogroup clustering in the study populations was also examined. A set of 48 bi-allelic markers on the non-recombining region of Y chromosome (NRY) were analysed in 284 males; representing nine Indo-European speaking tribal populations. The genetic structure of the populations revealed that none of these groups was overtly admixed or completely isolated. However, elevated haplogroup diversity and F_ST value point towards greater diversity and differentiation which suggests the possibility of early demographic expansion of the study groups. The phylogenetic analysis revealed 13 paternal lineages, of which six haplogroups: C5, H1a*, H2, J2, R1a1* and R2 accounted for a major portion of the Y chromosome diversity. The higher frequency of the six haplogroups and the pattern of clustering in the populations indicated overlapping of haplogroups with West and Central Asian populations. Other analyses undertaken on the population affiliations revealed that the Indo-European speaking populations along with the Dravidian speaking groups of southern India have an influence on the tribal groups of Gujarat. The vital role of geography in determining the distribution of Y lineages was also noticed. This implies that although language plays a vital role in determining the distribution of Y lineages, the present day linguistic affiliation of any population in India for reconstructing the demographic history of the country should be considered with caution.

Indian signatures in the westernmost edge of the European Romani diaspora: new insight from mitogenomes

In agreement with historical documentation, several genetic studies have revealed ancestral links between the European Romani and India. The entire mitochondrial DNA (mtDNA) of 27 Spanish Romani was sequenced in order to shed further light on the origins of this population. The data were analyzed together with a large published dataset (mainly hypervariable region I [HVS-I] haplotypes) of Romani (N=1,353) and non-Romani worldwide populations (N>150,000). Analysis of mitogenomes allowed the characterization of various Romani-specific clades. M5a1b1a1 is the most distinctive European Romani haplogroup; it is present in all Romani groups at variable frequencies (with only sporadic findings in non-Romani) and represents 18% of their mtDNA pool. Its phylogeographic features indicate that M5a1b1a1 originated 1.5 thousand years ago (kya; 95% CI: 1.3-1.8) in a proto-Romani population living in Northwest India. U3 represents the most characteristic Romani haplogroup of European/Near Eastern origin (12.4%); it appears at dissimilar frequencies across the continent (Iberia: ≈ 31%; Eastern/Central Europe: ≈ 13%). All U3 mitogenomes of our Iberian Romani sample fall within a new sub-clade, U3b1c, which can be dated to 0.5 kya (95% CI: 0.3-0.7); therefore, signaling a lower bound for the founder event that followed admixture in Europe/Near East. Other minor European/Near Eastern haplogroups (e.g. H24, H88a) were also assimilated into the Romani by introgression with neighboring populations during their diaspora into Europe; yet some show a differentiation from the phylogenetically closest non-Romani counterpart. The phylogeny of Romani mitogenomes shows clear signatures of low effective population sizes and founder effects. Overall, these results are in good agreement with historical documentation, suggesting that cultural identity and relative isolation have allowed the Romani to preserve a distinctive mtDNA heritage, with some features linking them unequivocally to their ancestral Indian homeland.

Reconstructing Roma history from genome-wide data

The Roma people, living throughout Europe and West Asia, are a diverse population linked by the Romani language and culture. Previous linguistic and genetic studies have suggested that the Roma migrated into Europe from South Asia about 1,000-1,500 years ago. Genetic inferences about Roma history have mostly focused on the Y chromosome and mitochondrial DNA. To explore what additional information can be learned from genome-wide data, we analyzed data from six Roma groups that we genotyped at hundreds of thousands of single nucleotide polymorphisms (SNPs). We estimate that the Roma harbor about 80% West Eurasian ancestry-derived from a combination of European and South Asian sources-and that the date of admixture of South Asian and European ancestry was about 850 years before present. We provide evidence for Eastern Europe being a major source of European ancestry, and North-west India being a major source of the South Asian ancestry in the Roma. By computing allele sharing as a measure of linkage disequilibrium, we estimate that the migration of Roma out of the Indian subcontinent was accompanied by a severe founder event, which appears to have been followed by a major demographic expansion after the arrival in Europe.