Project description:Hispanic/Latino populations possess a complex genetic structure that reflects recent admixture among and potentially ancient substructure within Native American, European, and West African source populations. Here, we quantify genome-wide patterns of SNP and haplotype variation among 100 individuals with ancestry from Ecuador, Colombia, Puerto Rico, and the Dominican Republic genotyped using Illumina technology.
Project description:Hispanic/Latino populations possess a complex genetic structure that reflects recent admixture among and potentially ancient substructure within Native American, European, and West African source populations. Here, we quantify genome-wide patterns of SNP and haplotype variation among 100 individuals with ancestry from Ecuador, Colombia, Puerto Rico, and the Dominican Republic genotyped using Illumina technology. To investigate variations of continental ancestry between different Hispanic/Latino groups (using self-reported country-specific identification of individual, both parents, and all four grandparents) and within them from healthy controls represented in the New York Health Project Biorepository. Genotyped on the Illumina 610-Quad, which is identical to HumanHap550-v3 SNPs plus an additional ~60,000 SNPs for CNV, no CNV data is provided or was analyzed.
Project description:A population and admixture analysis of Mesoamerican Totonacs and South American Bolivians. A panel of highly informative ancestry informative markers (AIMs) for New World populations is identified. Regions coinciding with AIMs are have moderate signatures of selection. Population structure and differentiation were assessed with a genome-wide panel of 815,377 autosomal markers, Y-chromosome STR and SNPs, and mtDNA sequence data.
Project description:The Kashmiri population is an ethno-linguistic group that resides in the Kashmir Valley in northern India. A longstanding hypothesis is that this population derives ancestry from Jewish and/or Greek sources. There is historical and archaeological evidence of ancient Greek presence in India and Kashmir. Further, some historical accounts suggest ancient Hebrew ancestry as well. To date, it has not been determined whether signatures of Greek or Jewish admixture can be detected in the Kashmiri population. Using genome-wide genotyping and admixture detection methods, we determined there are no significant or substantial signs of Greek or Jewish admixture in modern-day Kashmiris. The ancestry of Kashmiri Tibetans was also determined, which showed signs of admixture with populations from northern India and west Eurasia. These results contribute to our understanding of the existing population structure in northern India and its surrounding geographical areas.
Project description:<p>The GOAL Study was designed to comprehensively evaluate the genomic architecture of diverse Hispanic/Latino individuals with origins from the Caribbean, Central and South America, and to understand the impact of this diversity on genetic disease studies. Population structure and admixture are key confounders in genome-wide association and medical resequencing studies. In particular, accounting for difference in ancestry among cases and controls, both in terms of genomic and geographic location, is critical for proper analysis and interpretation of studies with multi- and trans-ethnic samples. Genomic studies of Hispanics/Latinos, the largest and fastest growing minority group in the US, reveal that they are a highly genetically heterogeneous admixed group with immense variation among individuals and populations in the proportions of African, European, and Native American ancestry. Knowledge of the underlying complex genetic structure of US Hispanic/Latino and Caribbean populations is, therefore, essential to ensuring robustness of genotype-phenotype associations and understanding the medical relevance of associated variants across diverse populations in the US and throughout the Americas. Furthermore, since much is known about the African and European migrations into the Americas over the past 500 years, population genetic studies of Hispanics/Latinos serve as an excellent model for developing novel algorithms and approaches for characterizing fine-scale genetic structure of admixed populations, in general. This project extends current studies of population genetic structure in US Hispanics/Latinos by densely genotyping parent-offspring triads from individuals (sampled in the US) of Caribbean-descent from six Latin American countries: Puerto Rico, Cuba, Dominican Republic, Haiti, Honduras and Colombia. This study will provide immediate insights and new statistical methods to improve study design and genetic analysis for medical genomic studies in Hispanics/Latinos, other complex admixed groups, and multi- and trans-ethnic studies.</p>
Project description:Affymetrix single nucleotide polymorphism (SNP) array data were collected to study genome-wide patterns of genomic variation across a broad geographical range of Island Southeast Asian populations. This region has experienced an extremely complex admixture history. Initially settled ~50,000 years ago, Island Southeast Asia has since been the recipient of multiple waves of population movements, most recently by Austronesian-speaking groups ultimately from Neolithic mainland Asia and later arrivals during the historic era from India and the Middle East. We have genotyped SNPs in ~500 individuals from 30 populations spanning this entire geographical region, from communities close to mainland Asia through to New Guinea. Particular attention has been paid to genomic data that are informative for population history, including the role of recent arrivals during the historic era and admixture with archaic hominins.
Project description:The genetic structure of some native Bolivians has been substantially influenced by admixture from Europeans, which we estimate to have occurred approximately 360 – 384 years ago. Consistent with historical accounts of male admixture, Y-chromosome haplogroups typical of Europeans were found in 39% of our Bolivian samples. No evidence of African admixture was found in native Bolivians. The Mesoamerican Totonacs have little evidence of European or African admixture. Our analysis indicates that some admixed Bolivians have Native American mtDNA and Y-chromosomes but harbor up to 30% European autosomal ancestry, demonstrating the need for autosomal markers to assess ancestry in admixed populations. From a dense genome-wide panel of 815,377 markers, we developed a set of 324 AIMs, specific for Native American ancestry. As few a 40-50 of these markers successfully predict New World ancestry in the ascertainment panel of Bolivians and Totonacs. The markers easily distinguish New World from Old World ancestry, even for populations more closely related to the Americas such as central and eastern Asians, and were effective for New World vs. Old World comparisons in five other geographically and culturally distinct populations of the Americas. SNPs demonstrating very high divergence between the two Native American populations and major Old World populations are found on haplotypes that are shared and occur at similar frequencies in other indigenous low-admixture American populations examined here (i.e. Pima, Maya, Colombian, Karitiana, and Surui). After excluding the possibility of recent relatedness, our results indicate that native Bolivians and Totonacs share ancestry with other American populations through a substantial contribution from a common founding population, population bottlenecks, and possible natural selection on functional variation.