Cardio-metabolic parameters are associated with genetic admixture estimates in a pediatric population from Colombia

ABSTRACT: There are different genetic patterns for cardio-metabolic parameters among different populations. Additionally, it has been found that ancestral genetic components (the proportion of Amerindian, European and African) in admixed Latin American populations influence an individual’s susceptibility to cardio-metabolic disorders. The aim of this study was to evaluate the effect of ancestral genetic composition on a series of cardio-metabolic risk factors in a young admixed population from Colombia. Results: In a sample of 853 Colombian youth, 10 to 18 years old, the mean European contribution was 66.6 % (range: 41–82 %), the mean African contribution was 14 % (range: 4–48 %), and the mean Amerindian contribution was 19.4 % (range: 10–35 %) using a panel of 40 autosomal ancestry-informative markers (AIMs). We assessed the degree of association between ancestral African, Amerindian and European genetic components and measures of body mass index, waist circumference, fasting glucose, fasting insulin, insulin resistance, triglycerides, high-density lipoprotein, and systolic and diastolic blood pressure. Two of the nine measures assessed presented a nominal significant association with ancestral components after adjusting for confounding variables: triglyceride levels were associated with the Amerindian component (OR = 1.06, 98.3 % CI = 1.01–1.11, P = 0.002) and systolic blood pressure was associated with the European component (OR = 0.93, 98.3 % CI = 0.87 to 0.99, P = 0.008) and the African component (OR = 1.07, CI = 1.01–1.14 P = 0.008), although it was not significant following a global Bonferroni correction. Additionally, insulin levels and insulin resistance showed associations with the African component. Conclusions: Our findings support the idea that an Amerindian ancestral component may act as a risk factor for high triglyceride levels. In addition, an African ancestral component confers a risk for high systolic blood pressure, and a European ancestry serves as a protective factor for this condition in a young admixed population from Colombia. However, these results should be confirmed in a larger population

Behavior of the mtDNA mutation A3243G in two antioquian families of patients with melas syndrome

ABSTRACT: Mitochondrial DNA mutations cause mitochondrial cytopathies. Among them Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes (MELA) is the commonest. The transition 3243A>G in the Leucine tRNA is present in 80% of the patients. Heteroplasmy is observed in mitochondrial cytopathies, characterized by the coexistence of mutant and wild type molecules in a cell. Depending on the level of heteroplasmy, function and clinical manifestations might result affected. Objective: To test the degree of heteroplasmy of the mutation 3243G on its expression (syntoms) and nuclear-variants dependence. Patients and methods: Mutations in the tRNALeu gene were sought in 34 patients by sequencing and PCR-RFLP. Four SPA (specific population alleles) were typed in patients and their relatives carrying the mutation 3243A>G. Results: The mutation 3243A>G in the Leucine tRNA gene was found in two patients. This mutation was screened in their relatives and the amount of mutant DNA (MDNA) was assessed. The index cases presented with the higher amounts of MDNA in both families. In family one, the mutation was detected in 14 members, three of which presented with short stature, one with hearing loss, one with type 2 diabetes, 8 with migraine and one healthy individual. In family two the mutation was detected in one member with brain paralysis, two with migraine and one healthy individual. Conclusions: Severity of the symptoms in patients affected with MELAS is correlated with the amount of MDNA. Furthermore, it was found a correlation between MDNA and IAA, suggesting a possible effect of amerind nuclear ontext in The mitochondrial segregation and replication.RESUMEN: Mutaciones en mtDNA causan citopatias mitocondriales, la más común de ellas es el síndrome MELAS; la transición A3243G en tRNA de leucina (tRNALeu) se presenta en 80% de pacientes. La heteroplasmia, observada en citopatias mitocondriales, consiste en coexistencia de moléculas mutadas y normales en una célula, situación en la cual, dependiendo de su cantidad, afecta su función con expresión clínica variable. Objetivo: evaluar el comportamiento de la cantidad de heteroplasmia de la mutación 3243G en su expresión clínica y en la dependencia de variantes nucleares. Pacientes y métodos: se buscaron mutaciones en el gen que codifica para el tRNA de leucina por secuencia y por PCR-RFLP en 34 pacientes, y se tamizó en familiares de los portadores de la mutación. Se tipificaron cuatro Specific Population Allele (SPA) en pacientes y familiares con la mutación A3243G. Resultados: se halló la mutación A3243G en el tRNALeu en dos pacientes, luego de tamizar la mutación A3243G en ambas familias se evaluó la cantidad de mtDNA mutado (MDNA), encontrando que los casos índices de ambas familias presentaron la mayor cantidad de MDNA; en la primera familia se detectó la mutación en 15 miembros que presentaron diversos síntomas. En la segunda familia se detectó la mutación en un miembro con parálisis cerebral, en dos con migraña y en uno asintomático. Conclusiones: la severidad de los síntomas se correlaciona con la cantidad de MDNA, se encontró además correlación entre mtDNA mutado (MDNA) y el Índice de Ancestría Amerindio en cada individuo (IAA), indicando una posible influencia del contexto nuclear amerindio en la segregación y replicación mitocondrial

Inbreeding, Native American ancestry and child mortality: linking human selection and paediatric medicine

The children of related parents show increased risk of early mortality. The Native American genome typically exhibits long stretches of homozygosity, and Latin Americans are highly heterogeneous regarding the individual burden of homozygosity, the proportion and the type of Native American ancestry. We analysed nationwide mortality and genome-wide genotype data from admixed Chileans to investigate the relationship between common causes of child mortality, homozygosity and Native American ancestry. Results from two-stage linear-Poisson regression revealed a strong association between the sum length of runs of homozygosity (SROH) above 1.5 Megabases (Mb) in each genome and mortality due to intracranial non-traumatic haemorrhage of foetus and newborn (5% increased risk of death per Mb in SROH, P = 1 × 10−3) and disorders related to short gestation and low birth weight (P = 3 × 10−4). The major indigenous populations in Chile are Aymara–Quechua in the north of the country and the Mapuche–Huilliche in the south. The individual proportion of Aymara–Quechua ancestry was associated with an increased risk of death due to anencephaly and similar malformations (P = 4 × 10−5), and the risk of death due to Edwards and Patau trisomy syndromes decreased 4% per 1% Aymara–Quechua ancestry proportion (P = 4 × 10−4) and 5% per 1% Mapuche–Huilliche ancestry proportion (P = 2 × 10−3). The present results suggest that short gestation, low birth weight and intracranial non-traumatic haemorrhage mediate the negative effect of inbreeding on human selection. Independent validation of the identified associations between common causes of child death, homozygosity and fine-scale ancestry proportions may inform paediatric medicine.Fil: Koenigstein, Fabienne. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Boekstegers, Felix. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Wilson, James F.. University of Edinburgh; Reino UnidoFil: Fuentes Guajardo, Macarena. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Bedoya Berrío, Gabriel. Universidad de Antioquia; ColombiaFil: Bortolini, Maria Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Acuña Alonzo, Victor. Instituto Nacional de Antropología e Historia. Escuela Nacional de Antropología e Historia; MéxicoFil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Ruiz-Linares, Andres. Fudan University; China. Aix-Marseille Université; Francia. Centre National de la Recherche Scientifique; Francia. University College London; Reino UnidoFil: Rothhammer, Francisco. Universidad de Tarapaca. Instituto de Alta Investigación; ChileFil: Lorenzo Bermejo, Justo. Ruprecht Karls Universitat Heidelberg; Alemani

Calidad de Vida Relacionada con la Salud en Un Grupo de Adolescentes de Medellín (Colombia): Asociación con Aspectos Sociodemográficos, Exceso de Peso u Obesidad y Actividad Física

El objetivo del estudio fue describir la calidad de vida relacionada con la salud (CVRS) y su asociación con aspectos sociodemográficos, el exceso de peso u obesidad y la actividad física (AF) en un grupo de adolescentes de la ciudad de Medellín (Colombia). Para evaluar dichas variables se aplicaron diferentes instrumentos a 399 participantes. Las dimensiones de la CVRS con mayores puntuaciones fueron Apoyo Social y Amigos y Estado de Ánimo y Sentimientos. Ser hombre, tener una menor edad, cursar primaria, tener padres con educación superior, pertenecer a estrato socioeconómico alto, no tener obesidad por porcentaje de grasa o perímetro abdominal y presentar un nivel alto de AF se relacionaron con una mejor CVRS

Prevalence of cardiovascular risk factors in the embera-chami indigenous population of Cristianía (Jardín) Antioquia, Colombia

ABSTRACT: Prevalence of cardiovascular risk factors was studied in 488 individuals over the age of 14 years in the Karmata Rua indigenous population of Cristianía, Colombia. The following rates were found: arterial hypertension 18.1%, family history of diabetes mellitus 3.3%, serum glucose over 126 mg/dL 0.7%, smoking habit 15%, overweight 40.2%, obesity 8.0%, hypercholesterolemia 21.4%, hypertriglyceridemia 33.3% and dyslipidemia 56.2%. Values of body mass index, total cholesterol, glucose, waist circumference, waist/hip index, systolic and diastolic blood pressure showed a positive and significant correlation with age. Higher level of education showed negative correlation with waist circumference, the waist/hip index, blood sugar and blood pressure. In comparison with other indigenous and non-indigenous communities of Colombia and other countries, prevalence of diabetes mellitus was between three and four times lower in the studied population; prevalence or high blood pressure was also lower despite a tendency to overweight. For other risk factors no significant differences were found, but they were more common in women, in people with low level of schooling and in elder individuals. Probably this difference is caused by genetic and environmental factors, such as increased physical activity in men, diet, and population structure.RESUMEN: Estudiamos la prevalencia de los factores de riesgo cardiovascular en 488 individuos mayores de 14 años, en el resguardo indígena Karmata Rúa de Cristianía. Se encontraron las siguientes frecuencias: hipertensión arterial (HTA) 18,1%; antecedente personal de diabetes mellitus 3,3%; glucemia mayor de 126 mg/dL 0,7%; hábito de fumar 15%; sobrepeso 40,2%; obesidad 8,0%; hipercolesterolemia 21,4%; hipertrigliceridemia 33,3% y dislipidemia 56,2%. El índice de masa corporal y los valores de colesterol total, glucemia, perímetro de la cintura, índice cintura/ cadera y presión arterial sistólica y diastólica presentaron correlación positiva y significativa con la edad. El grado de escolaridad mostró correlación negativa con el perímetro de la cintura, el índice cintura/cadera, la glucemia y la presión arterial. Al comparar con poblaciones indígenas y no indígenas de Colombia y de otros países, se encontró una prevalencia entre tres y cuatro veces menor de diabetes mellitus; en la población estudiada hay menos HTA aunque existe tendencia al sobrepeso. No se encontraron diferencias significativas en otros factores de riesgo; todos ellos fueron más frecuentes en mujeres, en personas de escolaridad baja y en individuos mayores. Los factores que contribuyen a estas diferencias son genéticos (homogeneidad étnica) y ambientales, como la mayor actividad física de los hombres, la dieta y la estructura demográfica

Epidemiology of chronic venous disorders and associated factors in embera-chamí native Amerindians, Antioquia

ABSTRACT: To analyze the prevalence of chronic venous disorders (CVD) in the embera-chamí from Cristianía (Karmata Rua), in the southwest of Antioquia, and to study posible associated factors (AF). Methodology: A cross sectional study of a random sample of 488 subjects. The diagnosis was performed through Doppler ultrasonography. Information about sociodemographic, behavioral and anthropometric AFs was collected. The most relevant AFs were selected through multiple binary logistic regression. Results: The prevalence of varicose veins was 27.5% and that of chronic venous insufficiency (cvi) was 0.8%. Superficial anatomical segments were compromised in 34.8% of individuals. Age was the most important AF, with an Odds Ratio (OR) between 3.33 and 6.30 according to the type of cvd. Being a female, parity, fat in the thigh/leg and large size were associated with telangiectasias. Age, abdominal fat and leg shape were AF of varicose veins. Superficial veins in both sexes were associated with age and abdominal fat and in women, also with a family background of varicose veins. Deep and perforator veins were associated with age and peripheral fat depletion. Conclusions: The low prevalence pattern of CVDs in embera-chamí may be a consequence of lifestyles involving daily physical activity and genetic differences shared with Amerindians. Deep and perforating disorders should be considered in differential health care programs in relation to mestizos. Keywords: chronic venous disorders, varicose veins, telangiectasias, chronic venous insufficiency, Amerindians, embera-chamí.RESUMEN:Analizar la prevalencia de los desórdenes venosos crónicos (dvc) en los embera-chamí de Cristianía (Karmata Rua), en el suroeste de Antioquia, y conocer sus posibles factores asociados (fa). Metodología: Estudio de corte de una muestra aleatoria de 488 sujetos. El diagnóstico se realizó mediante ecoduplex venoso. Se recolectó información sobre fa sociodemográficos, comportamentales y antropométricos. Los fa más relevantes se seleccionaron por regresión logística binaria múltiple. Resultados: La prevalencia de várices fue del 27,5 % y la de insuficiencia venosa crónica (ivc) del 0,8 %. Hubo compromiso de segmentos anatómicos superficiales en el 34,8 % de los individuos. La edad fue el fa más importante, con Odds Ratio (or) entre 3,33 y 6,30 según el tipo de dvc. El sexo femenino, la paridad, la grasa en el muslo y pierna y la talla alta se asociaron a telangiectasias. La edad, la grasa abdominal y la forma de la pierna fueron fa de várices. A las venas superficiales, en ambos sexos, se asociaron la edad y la grasa abdominal y, en mujeres, también los antecedentes familiares de várices. A las profundas y perforantes se asociaron la edad y la depleción de grasa periférica. Conclusiones: El patrón de baja prevalencia de los dvc en embera-chamí puede ser consecuencia de los estilos de vida relacionados con la actividad física diaria y las diferencias genéticas compartidas con amerindios. En los programas de atención en salud diferencial deberían considerarse los desórdenes profundos y perforantes respecto a mestizos. Palabras clave: desórdenes venosos crónicos, várices, telangiectasias, insuficiencia venosa crónica, amerindios, embera-chamí

Effect of an intervention with physical exercise and nutritional guidance on the components of the metabolic syndrome among young people with overweight

ABSTRACT: Interventions with physical exercise and nutritional guidance show changes in overweight among young people suffering from the metabolic syndrome (MS); nevertheless, their characteristics and results vary. Objective: To assess the effect of an intervention with physical exercise and nutritional guidance on components of the MS among overweighted young people. Materials and methods: Longitudinal study with an assessment before and another after the intervention in nine young people aged 11 to 17 years. Anthropometric aspects, resting heart rate, peak oxygen consumption (VO2peak), insulinemia, HOMA, and components of the MS were assessed. Intervention consisted of 12 weeks of supervised exercise, three 90-minute sessions/week (aerobic and strength), plus two unsupervised sessions; the weekly supply of fruits and vegetables in order to cover the five recommended daily servings, and individual and group nutrition education. Results: With the intervention waist circumference decreased from 90.5 ± 11.0 to 88.1 ± 9.9 cm; BMI from 30.2 ± 5.8 to 29.3 ± 5.6 kg/m2 ; total body fat from 39.8 ± 13.0 to 34.3 ± 9.0%; glycemia from 86.0 ± 8.6 to 83.1 ± 5.0 mg/dL; insulinemia from 23.2 ± 9.8 to 19.4 ± 7.6 µU/mL; HOMA-IR from 2.89 ± 1.21 to 2.39 ± 0.93; resting heart rate from 87.9 ± 4.3 to 78.2 ± 5.5 rpm, and VO2peak increased from 36.3 ± 5.1 to 38.5 ± 4.1 mL/kg/min. Four out of six young people with the diagnosis of MS at the beginning of the study did not present it at the end. Conclusions: Participating in an exercise program and increase in the consumption of fruits and vegetables among overweighted young people with components of the MS produced positive modifications in body composition, VO2peak, resting heart rate, and glycemia, as well as in the components and prevalence of the MS.RESUMEN: Las intervenciones con ejercicio físico y orientación nutricional muestran cambios en el exceso de peso en jóvenes con el síndrome metabólico (SM); sin embargo, sus características y resultados son diversos. Objetivo: evaluar el efecto de una intervención con ejercicio físico y orientación nutricional sobre componentes del SM en jóvenes con exceso de peso. Materiales y métodos: estudio longitudinal con una evaluación antes y otra después, en nueve jóvenes entre 11 y 17 años. Se evaluaron aspectos antropométricos, frecuencia cardíaca en reposo (FCR), consumo pico de oxígeno (VO2pico), insulinemia, resistencia a la insulina (HOMA) y componentes de SM. La intervención consistió en 12 semanas de ejercicio supervisado, tres sesiones/semana de 90 minutos (aeróbico y de fuerza), más dos sesiones no supervisadas; el suministro semanal de frutas y verduras para cubrir las cinco porciones diarias recomendadas y educación nutricional individual y colectiva. Resultados: luego de la intervención disminuyeron la circunferencia de la cintura de 90,5 ± 11,0 a 88,1 ± 9,9 cm; el IMC de 30,2 ± 5,8 a 29,3 ± 5,6 kg/m2 ; la grasa corporal total de 39,8 ± 13,0 a 34,3 ± 9,0%; la glucemia de 86,0 ± 8,6 a 83,1 ± 5,0 mg/dL; la insulinemia de 23,2 ± 9,8 a 19,4 ± 7,6 µU/mL; el HOMA-IR de 2,89 ± 1,21 a 2,39 ± 0,93; la FCR de 87,9 ± 4,3 a 78,2 ± 5,5 bpm y aumentó el VO2pico de 36,3 ± 5,1 a 38,5 ± 4,1 mL/kg/min; de seis jóvenes con diagnóstico de SM al inicio, cuatro no lo presentaron al final. Conclusiones: participar en un programa de ejercicio y aumentar el consumo de frutas y verduras en los jóvenes con exceso de peso y componentes del SM generó modificaciones positivas en la composición corporal, el VO2pico, la FCR y la glucemia así como en los componentes y prevalencia del SM

Native American ancestry significantly contributes to neuromyelitis optica susceptibility in the admixed Mexican population

Neuromyelitis Optica (NMO) is an autoimmune disease with a higher prevalence in non-European populations. Because the Mexican population resulted from the admixture between mainly Native American and European populations, we used genome-wide microarray, HLA high-resolution typing and AQP4 gene sequencing data to analyze genetic ancestry and to seek genetic variants conferring NMO susceptibility in admixed Mexican patients. A total of 164 Mexican NMO patients and 1,208 controls were included. On average, NMO patients had a higher proportion of Native American ancestry than controls (68.1% vs 58.6%; p = 5 × 10–6). GWAS identified a HLA region associated with NMO, led by rs9272219 (OR = 2.48, P = 8 × 10–10). Class II HLA alleles HLA-DQB1*03:01, -DRB1*08:02, -DRB1*16:02, -DRB1*14:06 and -DQB1*04:02 showed the most significant associations with NMO risk. Local ancestry estimates suggest that all the NMO-associated alleles within the HLA region are of Native American origin. No novel or missense variants in the AQP4 gene were found in Mexican patients with NMO or multiple sclerosis. To our knowledge, this is the first study supporting the notion that Native American ancestry significantly contributes to NMO susceptibility in an admixed population, and is consistent with differences in NMO epidemiology in Mexico and Latin America.Fil: Romero Hidalgo, Sandra. Instituto Nacional de Medicina Genómica; MéxicoFil: Flores Rivera, José. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Rivas Alonso, Verónica. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Barquera, Rodrigo. Max Planck Institute For The Science Of Human History; Alemania. Instituto Nacional de Antropología e Historia; MéxicoFil: Villarreal Molina, María Teresa. Instituto Nacional de Medicina Genómica; MéxicoFil: Antuna Puente, Bárbara. Instituto Nacional de Medicina Genómica; MéxicoFil: Macias Kauffer, Luis Rodrigo. Universidad Nacional Autónoma de México; MéxicoFil: Villalobos Comparán, Marisela. Instituto Nacional de Medicina Genómica; MéxicoFil: Ortiz Maldonado, Jair. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Yu, Neng. American Red Cross; Estados UnidosFil: Lebedeva, Tatiana V.. American Red Cross; Estados UnidosFil: Alosco, Sharon M.. American Red Cross; Estados UnidosFil: García Rodríguez, Juan Daniel. Instituto Nacional de Medicina Genómica; MéxicoFil: González Torres, Carolina. Instituto Nacional de Medicina Genómica; MéxicoFil: Rosas Madrigal, Sandra. Instituto Nacional de Medicina Genómica; MéxicoFil: Ordoñez, Graciela. Neuroimmunología, Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Guerrero Camacho, Jorge Luis. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Treviño Frenk, Irene. American British Cowdray Medical Center; México. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Escamilla Tilch, Monica. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: García Lechuga, Maricela. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Tovar Méndez, Víctor Hugo. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Pacheco Ubaldo, Hanna. Instituto Nacional de Antropología E Historia. Escuela Nacional de Antropología E Historia; MéxicoFil: Acuña Alonzo, Victor. Instituto Nacional de Antropología E Historia. Escuela Nacional de Antropología E Historia; MéxicoFil: Bortolini, María Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Bedoya Berrío, Gabriel. Universidad de Antioquia; ColombiaFil: Rothhammer, Francisco. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Ruiz Linares, Andrés. Colegio Universitario de Londres; Reino UnidoFil: Canizales Quinteros, Samuel. Universidad Nacional Autónoma de México; MéxicoFil: Yunis, Edmond. Dana Farber Cancer Institute; Estados UnidosFil: Granados, Julio. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Corona, Teresa. Instituto Nacional de Neurología y Neurocirugía; Méxic

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

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.Instituto Multidisciplinario de Biología Celula

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

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.Instituto Multidisciplinario de Biología Celula