Publications by authors named "María Laura Parolin"

11 Publications

  • Page 1 of 1

Prediction of eye, hair and skin colour in Latin Americans.

Forensic Sci Int Genet 2021 Apr 6;53:102517. Epub 2021 Apr 6.

Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK; Melbourne Integrative Genomics, Schools of BioSciences and Mathematics & Statistics, University of Melbourne, Melbourne, VIC 3010, Australia.

Here we evaluate the accuracy of prediction for eye, hair and skin pigmentation in a dataset of > 6500 individuals from Mexico, Colombia, Peru, Chile and Brazil (including genome-wide SNP data and quantitative/categorical pigmentation phenotypes - the CANDELA dataset CAN). We evaluated accuracy in relation to different analytical methods and various phenotypic predictors. As expected from statistical principles, we observe that quantitative traits are more sensitive to changes in the prediction models than categorical traits. We find that Random Forest or Linear Regression are generally the best performing methods. We also compare the prediction accuracy of SNP sets defined in the CAN dataset (including 56, 101 and 120 SNPs for eye, hair and skin colour prediction, respectively) to the well-established HIrisPlex-S SNP set (including 6, 22 and 36 SNPs for eye, hair and skin colour prediction respectively). When training prediction models on the CAN data, we observe remarkably similar performances for HIrisPlex-S and the larger CAN SNP sets for the prediction of hair (categorical) and eye (both categorical and quantitative), while the CAN sets outperform HIrisPlex-S for quantitative, but not for categorical skin pigmentation prediction. The performance of HIrisPlex-S, when models are trained in a world-wide sample (although consisting of 80% Europeans, https://hirisplex.erasmusmc.nl), is lower relative to training in the CAN data (particularly for hair and skin colour). Altogether, our observations are consistent with common variation of eye and hair colour having a relatively simple genetic architecture, which is well captured by HIrisPlex-S, even in admixed Latin Americans (with partial European ancestry). By contrast, since skin pigmentation is a more polygenic trait, accuracy is more sensitive to prediction SNP set size, although here this effect was only apparent for a quantitative measure of skin pigmentation. Our results support the use of HIrisPlex-S in the prediction of categorical pigmentation traits for forensic purposes in Latin America, while illustrating the impact of training datasets on its accuracy.
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http://dx.doi.org/10.1016/j.fsigen.2021.102517DOI Listing
April 2021

New Evidence of Ancient Mitochondrial DNA of the Southern Andes (Calchaquí Valleys, Northwest Argentina, 3,600-1,900 Years before Present).

Hum Biol 2020 08;91(4):225-247

CONICET-Universidad de Buenos Aires, Instituto de las Culturas (IDECU), Buenos Aires, Argentina.

Genetic studies on pre-Hispanic populations of the Southern Andes have been increasing steadily in the last decade. Nevertheless, ancient DNA characterization of Formative Period archaeological human remains is particularly scant, especially for Northwest Argentina. To expand current information on genetic characterization of the first agricultural communities of the southern Calchaquí Valleys, we present and discuss the first mitochondrial ancient DNA information obtained on samples dated to ca. 3,600-1,900 years before present from the Cajón Valley, Catamarca Province. Reproducible mtDNA hypervariable region 1 (HVR-1) sequences were obtained in seven individuals. Mitochondrial HVR-1 haplotypes were assigned to three of the four founding haplogroups, D1 (57.1%), C1 (28.5%), and B2 (14.2%), with absence of A2. Our results show that the Cajón Valley sample, with predominance of D1 and C1, differs from that commonly observed in ancient and modern Andean populations, which usually show a high prevalence of haplogroup B2. The fact that the Cajón Valley and Pampa Grande (Salta Province, Argentina) share a prevalence of haplogroup D1 could provide additional evidence to support possible genetic affinities between the valleys and the eastern sub-Andean region during the Formative Period in Northwest Argentina, expanding the archaeological evidence of contact between both populations. Future complete mitogenomic analysis will provide substantial information to formulate new hypotheses about the origins and phylogenetic relationships between the individuals of the Cajón Valley and other groups from the Andes, Gran Chaco, and the Amazon.
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http://dx.doi.org/10.13110/humanbiology.91.4.02DOI Listing
August 2020

Fine-scale genomic analyses of admixed individuals reveal unrecognized genetic ancestry components in Argentina.

PLoS One 2020 16;15(7):e0233808. Epub 2020 Jul 16.

Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.

Similarly to other populations across the Americas, Argentinean populations trace back their genetic ancestry into African, European and Native American ancestors, reflecting a complex demographic history with multiple migration and admixture events in pre- and post-colonial times. However, little is known about the sub-continental origins of these three main ancestries. We present new high-throughput genotyping data for 87 admixed individuals across Argentina. This data was combined to previously published data for admixed individuals in the region and then compared to different reference panels specifically built to perform population structure analyses at a sub-continental level. Concerning the Native American ancestry, we could identify four Native American components segregating in modern Argentinean populations. Three of them are also found in modern South American populations and are specifically represented in Central Andes, Central Chile/Patagonia, and Subtropical and Tropical Forests geographic areas. The fourth component might be specific to the Central Western region of Argentina, and it is not well represented in any genomic data from the literature. As for the European and African ancestries, we confirmed previous results about origins from Southern Europe, Western and Central Western Africa, and we provide evidences for the presence of Northern European and Eastern African ancestries.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233808PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7365470PMC
September 2020

Genetic admixture patterns in Argentinian Patagonia.

PLoS One 2019 17;14(6):e0214830. Epub 2019 Jun 17.

Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal.

As in other Latin American populations, Argentinians are the result of the admixture amongst different continental groups, mainly from America and Europe, and to a lesser extent from Sub-Saharan Africa. However, it is known that the admixture processes did not occur homogeneously throughout the country. Therefore, considering the importance for anthropological, medical and forensic researches, this study aimed to investigate the population genetic structure of the Argentinian Patagonia, through the analysis of 46 ancestry informative markers, in 433 individuals from five different localities. Overall, in the Patagonian sample, the average individual ancestry was estimated as 35.8% Native American (95% CI: 32.2-39.4%), 62.1% European (58.5-65.7%) and 2.1% African (1.7-2.4%). Comparing the five localities studied, statistically significant differences were observed for the Native American and European contributions, but not for the African ancestry. The admixture results combined with the genealogical information revealed intra-regional variations that are consistent with the different geographic origin of the participants and their ancestors. As expected, a high European ancestry was observed for donors with four grandparents born in Europe (96.8%) or in the Central region of Argentina (85%). In contrast, the Native American ancestry increased when the four grandparents were born in the North (71%) or in the South (61.9%) regions of the country, or even in Chile (60.5%). In summary, our results showed that differences on continental ancestry contribution have different origins in each region in Patagonia, and even in each locality, highlighting the importance of knowing the origin of the participants and their ancestors for the correct interpretation and contextualization of the genetic information.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214830PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6576754PMC
February 2020

Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance.

Nat Commun 2018 12 19;9(1):5388. Epub 2018 Dec 19.

Servicio de Huellas Digitales Genéticas and CONICET, Universidad de Buenos Aires, Buenos Aires, C1113AAD, Argentina.

Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming mostly from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that ancestry related to highland (Central Andean) versus lowland (Mapuche) Natives is associated with variation in facial features, particularly nose morphology, and detect significant differences in allele frequencies between these groups at loci previously associated with nose morphology in this sample.
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http://dx.doi.org/10.1038/s41467-018-07748-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6300600PMC
December 2018

Historical records under the genetic evidence: "Chiriguano" tribe genesis as a test case.

Mol Biol Rep 2018 Oct 12;45(5):987-1000. Epub 2018 Jul 12.

Cátedra de Genética Forense y Servicio de Huellas Digitales Genéticas, Departamento de Microbiología, Inmunología y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, C1113AAD, Buenos Aires, Argentina.

Historical records suggest that Chiriguano tribe is the result of a genetic admixture event. The process involved the arrival of Guaraní tribesmen descending from Amazonian region of Brazil along with groups of Arawak origin that inhabited the foothill plains of Bolivia. Later they arrived in Argentina at the beginning of the twentieth century. Aiming to test the historical records, we analysed a set of 46 samples collected at San Ramon de la Nueva Orán, Province of Salta, Argentina. A wide set of uni- and biparentally transmitted genetic markers were analysed, including 23 autosomal STRs; 46 AIM-DIPs and 24 AIM-SNPs all located at diverse autosomal chromosome locations; 23 Y-STRs and the entire mtDNA D-Loop sequence. Ancestry informative markers allowed for the detection of a strong Native American component in the genomes (> 94%), while all mtDNA haplotypes showed Native American characteristic motives, and 93% of Y-haplotypes belonged to the Q1a3a Y-haplogroup. The analysis of mitochondrial haplotypes and Y chromosome, although they did not match other populations, revealed a relationship between the Chiriguano and other groups of Guaraní and Arawak origin inhabiting Brazil and Bolivia, confirming, at least in part, the historical records describing the origins of Chiriguano tribal settlements in northwestern Argentina.
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http://dx.doi.org/10.1007/s11033-018-4246-0DOI Listing
October 2018

Population genetic analyses of the Powerplex(®) Fusion kit in a cosmopolitan sample of Chubut Province (Patagonia Argentina).

Forensic Sci Int Genet 2015 Nov 1;19:221-222. Epub 2015 Aug 1.

Laboratorio de Identificación Genética (IDEGEN), Instituto de Diversidad y Evolución Austral (IDEAus-CONICET), Bvd. Brown, 2915 Puerto Madryn, Argentina.

Allele frequencies and forensic parameters for 22 autosomal STR loci and DYS391 locus included in the PowerPlex(®) Fusion System kit were estimated in a sample of 770 unrelated individuals from Chubut Province, southern Patagonia. No significant deviations from Hardy-Weinberg equilibrium were observed after Bonferroni's correction. The combined power of discrimination and the combined probability of exclusion were >0.999999 and 0.999984, respectively. Comparisons with other worldwide populations were performed. The MDS obtained show a close biological relation between Chubut and Chile. The estimated interethnic admixture supports a high Native American contribution (46%) in the population sample of Chubut. These results enlarge the Argentine databases of autosomal STR and would provide a valuable contribution for identification tests and population genetic studies.
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http://dx.doi.org/10.1016/j.fsigen.2015.07.020DOI Listing
November 2015

Population data of 15 autosomal STR markers from Afro-Bolivians of Nor Yungas Province (Bolivia).

Int J Legal Med 2015 May 9;129(3):463-4. Epub 2014 Sep 9.

Sistemática y Evolución, Laboratorio de Biología Molecular, Centro Nacional Patagónico-CONICET, Unidad de Diversidad, Bvd. Brown 2915, Puerto Madryn, Chubut, Argentina,

Allele frequencies and forensic parameters for 15 autosomal loci included in the AmpFlSTR® Identifiler kit were estimated in a sample of 57 unrelated Afro-descendants from Nor Yungas (Bolivia). Buccal swabs samples were obtained from voluntary donors, after consent was given. All loci were in Hardy-Weinberg equilibrium after Bonferroni correction. D21S11 was the most informative locus, while the least discriminating locus was D3S1358. The combined power of discrimination and the combined probability of exclusion were >0.99999999 and >0.99997, respectively. The multidimensional scaling (MDS) plot generated by Rst matrix supported that Afro-Bolivians of Nor Yungas preserved a stronger African descent compared to other admixed Latin American populations. These results amplified the Bolivian databases of autosomal STR loci and may provide a useful tool for human identification tests and population genetic studies.
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http://dx.doi.org/10.1007/s00414-014-1080-3DOI Listing
May 2015

Forensic population data for 20 STR loci in Argentina.

Forensic Sci Int Genet 2014 Nov 21;13:e20-1. Epub 2014 Jul 21.

LIDMO, Córdoba, Argentina. Electronic address:

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http://dx.doi.org/10.1016/j.fsigen.2014.07.008DOI Listing
November 2014

Analysis of 15 autosomal STR loci from Mar del Plata and Bahia Blanca (Central Region of Argentina).

Int J Legal Med 2014 May 21;128(3):457-9. Epub 2013 Nov 21.

Unidad de Diversidad, Sistemática y Evolución, Laboratorio de Biologia Molecular, Centro Nacional Patagonico-CONICET, Bvd. Brown 2915, Puerto Madryn, Chubut, Argentina,

Allele frequencies for the 15 short tandem repeats (STRs) loci included in the AmpFlSTR® Identifiler kit were estimated in a sample of unrelated individuals from Mar del Plata (MDQ; N = 180) and Bahia Blanca (BB; N = 85) (Buenos Aires, Argentina). Biological samples were obtained from voluntary donors and forensic cases. Both populations were in Hardy-Weinberg equilibrium after Bonferroni correction, except for locus vWA in MDQ and D2S1338 in BB. FGA was the most informative locus, and the least discriminating locus was TPOX in both samples. The combined power of discrimination (PDc) and the combined probability of exclusion (PEc) were similar in MDQ and BB samples (0.999999998 < PDc < 0.999999999 and 0.999999979 < PEc < 0.999999989). The multidimentional scaling plot from Rst genetic distance matrix and the interethnic admixture estimation supported a higher European contribution in populations of the central region compared with populations from other regions of Argentina with higher Amerindian composition. These results enlarge the Argentine databases of autosomal STR loci, revealed as an excellent tool for human identification tests and population genetic analysis.
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http://dx.doi.org/10.1007/s00414-013-0937-1DOI Listing
May 2014

Heterogeneity in genetic admixture across different regions of Argentina.

PLoS One 2012 10;7(4):e34695. Epub 2012 Apr 10.

Departamento de Antropología, University of Buenos Aires, Buenos Aires, Argentina.

The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63-68%), 31% Indigenous American (28-33%) and 4% African (3-4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73-79%; Northeast (NEA) 54%, 95%CI: 49-58%; Northwest (NWA) 33%, 95%CI: 21-41%; South 54%, 95%CI: 49-59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75-86%) versus 68% (95%CI: 58-77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88-94%) compared to 54% (95%CI: 51-57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0034695PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323559PMC
October 2012