RESUMO
Several studies have shown that the Brazilian Northeast is a region with high rates of inbreeding as well as a high incidence of autosomal recessive diseases. The elaboration of public health policies focused on the epidemiological surveillance of congenital anomalies and rare genetic diseases in this region is urgently needed. However, the vast territory, socio-demographic heterogeneity, economic difficulties and low number of professionals with expertise in medical genetics make strategic planning a challenging task. Surnames can be compared to a genetic system with multiple neutral alleles and allow some approximation of population structure. Here, surname analysis of more than 37 million people was combined with health and socio-demographic indicators covering all 1794 municipalities of the nine states of the region. The data distribution showed a heterogeneous spatial pattern (Global Moran Index, GMI = 0.58; p < 0.001), with higher isonymy rates in the east of the region and the highest rates in the Quilombo dos Palmares region - the largest conglomerate of escaped slaves in Latin America. A positive correlation was found between the isonymy index and the frequency of live births with congenital anomalies (r = 0.268; p < 0.001), and the two indicators were spatially correlated (GMI = 0.50; p < 0.001). With this approach, quantitative information on the genetic structure of the Brazilian Northeast population was obtained, which may represent an economical and useful tool for decision-making in the medical field.
Assuntos
Genética Médica/estatística & dados numéricos , Genética Populacional/estatística & dados numéricos , Nomes , Adolescente , Adulto , Idoso , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional , Adulto JovemRESUMO
In this study, we report for the first time HLA allele and haplotype frequencies in the modern Panamanian population at a two-field (four digits) resolution level. Reported frequencies were calculated from genotype data for the HLA-A, -B, -C, -DPB1, -DQB1 and -DRB1 loci of 462 healthy unrelated Panamanian adults of Hispanic ethnicity. In addition to providing new insights on the allelic structure of the Panamanian population and its origin, these data are critical for better planning of healthcare strategies in the country and for future research exploring the association with certain chronic and infectious diseases.
Assuntos
Hispânico ou Latino/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Adolescente , Adulto , Idoso , Alelos , Feminino , Frequência do Gene , Genética Populacional/estatística & dados numéricos , Haplótipos , Voluntários Saudáveis , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Panamá , Adulto JovemRESUMO
We investigated HLA class I (HLA-A, -B, and -C) and class II (HLA-DRB1, -DQB1, -DPA1, and -DPB1) alleles by NGS-based typing among 478 Brazilian individuals from two populations in the Barra Mansa city based on their self-declared skin color (Caucasian, N = 405, AFND-ID: 3729; Black, N = 73, AFND-ID: 3731) to calculate allelic and haplotypic frequencies, plus linkage disequilibrium. No locus deviated from Hardy-Weinberg equilibrium. Both populations shared the most frequent allele on HLA-A, -C, -DPA1, and -DPB1. Genotype and frequency data are available in the Allele Frequencies Net Database.
Assuntos
Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Alelos , Brasil , Frequência do Gene , Genética Populacional/estatística & dados numéricos , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Desequilíbrio de Ligação , Grupos Populacionais/genéticaRESUMO
We investigated HLA class I (HLA-A, -B, and -C) and class II (HLA-DRB1, -DQB1, -DPA1, and -DPB1) alleles by NGS-based typing among 759 Brazilian individuals from three populations in the Rio de Janeiro city based on their self-declared skin color (Caucasian, N = 521, AFND-ID: 3730; Parda, N = 170, AFND-ID: 3728; Black, N = 68, AFND-ID: 3727) to calculate allelic and haplotypic frequencies, plus linkage disequilibrium. Only HLA-DRB1 locus deviated from Hardy-Weinberg equilibrium (in Caucasian and Black populations). The three populations shared the most frequent allele on HLA-A, -C, -DRB1, -DPA1, and -DPB1. Genotype and frequency data are available in the Allele Frequencies Net Database.
Assuntos
Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Alelos , Brasil , Frequência do Gene , Genética Populacional/estatística & dados numéricos , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Desequilíbrio de Ligação , Grupos Populacionais/genéticaRESUMO
Breeding strategies based on molecular markers have been adopted by ex-situ conservation programs to assess alternative parameters for the genetic diversity estimates. In this work we evaluated molecular and studbook data for captive populations of black-lion-tamarin (BLT), an endangered primate endemic to Brazil's Atlantic Forest. Pedigree analyses were performed using BLT studbook information collected from 1973 to 2018. We analyzed the whole captive population since its foundation; the current captive population (CCP); and all extant BLTs in the Brazilian captive population (BCP), separately. Microsatellite analyses were implemented on the BCP individuals from the eighth generation (BCP-F8) only to avoid generation overlap. The expected heterozygosity for BCP-F8, using molecular, data was 0.45, and the initial expected heterozygosity was 0.69. Kinship parameters showed high genetic relationships in both pedigree and molecular analyses. The genealogy-based endogamy evidenced a high inbreeding coefficient, while the molecular analyses suggested a non-inbreeding signature. The Mate Suitability Index showed detrimental values for the majority of potential pairs in the CCP. Nevertheless, some individuals evidenced high individual heterozygosity and allele representation, demonstrating good potential to be used as breeders. Thus, we propose the use of molecular data as a complementary parameter to evaluate mating-pairs and to aid management decision-making.
Assuntos
Espécies em Perigo de Extinção , Variação Genética , Genética Populacional/métodos , Leontopithecus/genética , Animais , Animais de Zoológico , Brasil , Cruzamento , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/estatística & dados numéricos , Feminino , Florestas , Genética Populacional/estatística & dados numéricos , Genótipo , Heterozigoto , Masculino , Linhagem , Dinâmica PopulacionalRESUMO
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.
Assuntos
Etnicidade/genética , Genética Populacional/estatística & dados numéricos , Argentina/etnologia , População Negra , Humanos , Indígenas Norte-Americanos , Linhagem , População BrancaRESUMO
Population genetic data for 21 X-chromosome markers (Alu insertions and STRs) are reported for two populations (rural and urban) in Salta province (north-western Argentina). New variants are described, confirming the complexity and variability of some markers in this set. Results reveal Salta populations harbor a high Native American component, despite their self-recognized European ancestry. Notwithstanding the high genetic similarity of both populations, the rural sample seems to have maintained a larger Amerindian legacy. Data further show these X-linked markers, especially STRs, are highly informative in Salta populations and, therefore, can contribute to the development of a local database for forensic purposes in north-western Argentina.
Assuntos
Cromossomos Humanos X/genética , Indígenas Sul-Americanos/genética , Polimorfismo Genético/genética , População Rural/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Argentina , Frequência do Gene , Variação Genética , Genética Populacional/estatística & dados numéricos , HumanosRESUMO
Copy number variants (CNVs) are an important source of genomic structural variation, recognized to influence phenotypic variation in many species. Many studies have focused on identifying CNVs within and between human and livestock populations alike, but only few have explored population-genetic properties in cattle based on CNVs derived from a high-density SNP array. We report a high-resolution CNV scan using Illumina's 777k BovineHD Beadchip for Valdostana Red Pied (VRP), an autochthonous Italian dual-purpose cattle population reared in the Alps that did not undergo strong selection for production traits. After stringent quality control and filtering, CNVs were called across 108 bulls using the PennCNV software. A total of 6,784 CNVs were identified, summarized to 1,723 CNV regions (CNVRs) on 29 autosomes covering a total of ~59 Mb of the UMD3.1 assembly. Among the mapped CNVRs, there were 812 losses, 832 gains and 79 complexes. We subsequently performed a comparison of CNVs detected in the VRP and those available from published studies in the Italian Brown Swiss (IBS) and Mexican Holstein (HOL). A total of 171 CNVRs were common to all three breeds. Between VRP and IBS, 474 regions overlapped, while only 313 overlapped between VRP and HOL, indicating a more similar genetic background among populations with common origins, i.e. the Alps. The principal component, clustering and admixture analyses showed a clear separation of the three breeds into three distinct clusters. In order to describe the distribution of CNVs within and among breeds we used the pair VST statistic, considering only the CNVRs shared to more than 5 individuals (within breed). We identified unique and highly differentiated CNVs (n = 33), some of which could be due to specific breed selection and adaptation. Genes and QTL within these regions were characterized.
Assuntos
Bovinos/genética , Variações do Número de Cópias de DNA , Animais , Cruzamento , Bovinos/classificação , Mapeamento Cromossômico/veterinária , Indústria de Laticínios , Genética Populacional/estatística & dados numéricos , Itália , Masculino , México , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Locos de Características Quantitativas , Software , Especificidade da EspécieRESUMO
The analysis of genomic data (~400,000 autosomal SNPs) enabled the reliable estimation of inbreeding levels in a sample of 541 individuals sampled from a highly admixed Brazilian population isolate (an African-derived quilombo in the State of São Paulo). To achieve this, different methods were applied to the joint information of two sets of markers (one complete and another excluding loci in patent linkage disequilibrium). This strategy allowed the detection and exclusion of markers that biased the estimation of the average population inbreeding coefficient (Wright's fixation index FIS), which value was eventually estimated as around 1% using any of the methods we applied. Quilombo demographic inferences were made by analyzing the structure of runs of homozygosity (ROH), which were adapted to cope with a highly admixed population with a complex foundation history. Our results suggest that the amount of ROH <2Mb of admixed populations should be somehow proportional to the genetic contribution from each parental population.
Assuntos
Consanguinidade , Genética Populacional/métodos , Genética Populacional/estatística & dados numéricos , População Negra/estatística & dados numéricos , Brasil/epidemiologia , Feminino , Marcadores Genéticos , Genômica/métodos , Homozigoto , Humanos , Desequilíbrio de Ligação , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único , Estatística como Assunto/métodosRESUMO
We identified mitochondrial DNA haplogroups A, B, C, and D in 75 present-day Maya individuals, 24 Maya individuals of the colonial period, and 1 pre-Columbian Maya individual from Quintana Roo, Mexico. We examined these data together with those of 21 Maya populations reported in the literature, comprising 647 present-day Maya individuals and 71 ancient Maya individuals. A demographic study based on analysis of fertility and endogamy was carried out in two modern Maya populations to identify cultural factors that influence the mitochondrial haplogroup genetic diversity. Most present-day and ancient Maya populations show a distribution pattern of mitochondrial haplogroup frequencies A, C, B, and D in decreasing order, with haplogroup D absent in several populations. Considering only modern Maya populations with at least 50 individuals analyzed, the present-day Tzotzil and Lacandon populations from Chiapas show the highest and lowest genetic diversity, 0.706 and 0.025, respectively. Our results show small genetic differences between the Maya populations, with the exception of the present-day Tojolabal and Lacandon populations from Chiapas. The present-day Lacandon population from Chiapas differs from other Maya populations in showing almost only haplogroup A. This result suggests a long history of isolation and endogamy as well as a possible founder effect inside the Lacandonian rain forest. The contemporary Tojolabal population is the only one with an unusual mitochondrial haplogroup pattern, exhibiting a frequency of haplogroup B higher than A and the absence of haplogroup C. With a small sample size, the pre-Columbian Copán Maya show a high content of haplogroup C and a low frequency of haplogroup D. The genetic homogeneity of the Maya populations is indicative of a common origin and nearly continuous gene flow in the long term within a general isolation of the whole group, in contrast to the Nahua populations that had different origins. Our demographic study showed high fertility rates and high levels of endogamy in the present-day Maya populations from Quintana Roo that are consistent with their general low genetic diversity. We propose that the genetic similarity among ancient and present-day Maya populations persists due to a strong sense of social cohesion and identity that impacts their marriage practices, keeping this cultural group isolated. These factors have constrained gene flow inside the Maya region and have impeded the differentiation among the Maya. Discernment of genetic differentiation within the peninsula is constrained by the lack of sampling documentation in the literature.
Assuntos
DNA Mitocondrial/genética , Fluxo Gênico , Genética Populacional/estatística & dados numéricos , Haplótipos/genética , Indígenas Norte-Americanos/genética , Adolescente , Adulto , Evolução Molecular , Feminino , Variação Genética/genética , Humanos , Masculino , México/etnologia , Filogenia , Adulto JovemRESUMO
Genetic association studies determine how genes influence traits. However, non-detected population substructure may bias the analysis, resulting in spurious results. One method to detect substructure is to genotype ancestry informative markers (AIMs) besides the candidate variants, quantifying how much ancestral populations contribute to the samples' genetic background. The present study aimed to use a minimum quantity of markers, while retaining full potential to estimate ancestries. We tested the feasibility of a subset of the 12 most informative markers from a previously established study to estimate influence from three ancestral populations: European, African and Amerindian. The results showed that in a sample with a diverse ethnicity (N = 822) derived from 1000 Genomes database, the 12 AIMs had the same capacity to estimate ancestries when compared to the original set of 128 AIMs, since estimates from the two panels were closely correlated. Thus, these 12 SNPs were used to estimate ancestry in a new sample (N = 192) from an admixed population in Recife, Northeast Brazil. The ancestry estimates from Recife subjects were in accordance with previous studies, showing that Northeastern Brazilian populations show great influence from European ancestry (59.7%), followed by African (23.0%) and Amerindian (17.3%) ancestries. Ethnicity self-classification according to skin-color was confirmed to be a poor indicator of population substructure in Brazilians, since ancestry estimates overlapped between classifications. Thus, our streamlined panel of 12 markers may substitute panels with more markers, while retaining the capacity to control for population substructure and admixture, thereby reducing sample processing time.
Assuntos
Indígena Americano ou Nativo do Alasca/genética , População Negra/genética , Polimorfismo de Nucleotídeo Único , População Branca/genética , Indígena Americano ou Nativo do Alasca/etnologia , Indígena Americano ou Nativo do Alasca/estatística & dados numéricos , População Negra/etnologia , População Negra/estatística & dados numéricos , Brasil , Feminino , Frequência do Gene , Genética Populacional/métodos , Genética Populacional/estatística & dados numéricos , Genótipo , Humanos , Masculino , População Branca/etnologia , População Branca/estatística & dados numéricosRESUMO
Microsatellites are commonly used to understand genetic diversity among livestock populations. Nevertheless, most studies have involved the processing of samples in one laboratory or with common standards across laboratories. Our objective was to identify an approach to facilitate the merger of microsatellite data for cross-country comparison of genetic resources when samples were not evaluated in a single laboratory. Eleven microsatellites were included in the analysis of 13 US and 9 Brazilian sheep breeds (N = 706). A Bayesian approach was selected and evaluated with and without a shared set of samples analyzed by each country. All markers had a posterior probability of greater than 0.5, which was higher than predicted as reasonable by the software used. Sensitivity analysis indicated no difference between results with or without shared samples. Cluster analysis showed breeds to be partitioned by functional groups of hair, meat, or wool types (K = 7 and 12 of STRUCTURE). Cross-country comparison of hair breeds indicated substantial genetic distances and within breed variability. The selected approach can facilitate the merger and analysis of microsatellite data for cross-country comparison and extend the utility of previously collected molecular markers. In addition, the result of this type of analysis can be used in new and existing conservation programs.
Assuntos
Genética Populacional/métodos , Repetições de Microssatélites , Ovinos/genética , Alelos , Animais , Teorema de Bayes , Brasil , Cruzamento , Análise por Conglomerados , Conservação dos Recursos Naturais/estatística & dados numéricos , Bases de Dados Genéticas , Marcadores Genéticos , Variação Genética , Genética Populacional/estatística & dados numéricos , Cabelo , Carne , Software , Estados Unidos , LãRESUMO
The statement that pairs of individuals from different populations are often more genetically similar than pairs from the same population is a widespread idea inside and outside the scientific community. Witherspoon et al. ["Genetic similarities within and between human populations," Genetics 176:351-359 (2007)] proposed an index called the dissimilarity fraction (omega) to access in a quantitative way the validity of this statement for genetic systems. Witherspoon demonstrated that, as the number of loci increases, omega decreases to a point where, when enough sampling is available, the statement is false. In this study, we applied the dissimilarity fraction to Howells's craniometric database to establish whether or not similar results are obtained for cranial morphological traits. Although in genetic studies thousands of loci are available, Howells's database provides no more than 55 metric traits, making the contribution of each variable important. To cope with this limitation, we developed a routine that takes this effect into consideration when calculating omega. Contrary to what was observed for the genetic data, our results show that cranial morphology asymptotically approaches a mean omega of 0.3 and therefore supports the initial statement--that is, that individuals from the same geographic region do not form clear and discrete clusters--further questioning the idea of the existence of discrete biological clusters in the human species. Finally, by assuming that cranial morphology is under an additive polygenetic model, we can say that the population history signal of human craniometric traits presents the same resolution as a neutral genetic system dependent on no more than 20 loci.
Assuntos
Cefalometria/estatística & dados numéricos , Variação Genética , Genética Populacional/estatística & dados numéricos , África , Ásia , Cefalometria/métodos , Intervalos de Confiança , Bases de Dados Factuais , Europa (Continente) , Feminino , Marcadores Genéticos , Humanos , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único , Valores de ReferênciaRESUMO
Hemoglobin profile studies have been carried out in four samples from different districts of Porto Velho (Rondônia State) in the western Amazonian region of Brazil: Candelária, Bate Estaca, Hemeron (at the State Blood Bank), and São Carlos. Samples from 337 unrelated individuals were collected during medical and paramedical team visits by professionals from the Instituto de Pesquisa em Patologia Tropical and the Centro de Pesquisa em Patologias Tropicais (both research institutes in tropical diseases). The aim of this study is to assess the frequency of alleles in the hemoglobin system, mainly alleles HB*A, *S, and *E. The overall phenotype frequencies were HB A,S = 0.025, HB A,E = 0.006, and HB A,A = 0.969. Samples from the blood bank subjects and samples from the homogeneous areas of São Carlos and Candelária plus Bate Estaca have a chi-square of heterogeneity of 6.383 (p = 0.041) and 8.406 (p = 0.015), respectively. The allele frequencies (HB*A = 0.984, HB*S = 0.012, and HB*E = 0.003) do not significantly differ from frequencies found in other Brazilian regions.
Assuntos
Frequência do Gene , Genética Populacional/estatística & dados numéricos , Hemoglobina A/genética , Hemoglobina E/genética , Hemoglobina Falciforme/genética , Polimorfismo Genético/genética , Animais , População Negra/genética , Brasil , Emigração e Imigração , Fluxo Gênico/genética , Deriva Genética , Humanos , Indígenas Sul-Americanos/genética , Funções Verossimilhança , Malária/sangue , Malária/genética , Malária/prevenção & controle , Fenótipo , Plasmodium/genética , População Branca/genéticaRESUMO
Restriction fragment length polymorphisms are good anthropological markers for discriminating geographically distinct populations at both the allele and the haplotype level. Two communities of African ancestry and ladinos, mestizos, and mulattoes living in the Esmeraldas province in northwestern Ecuador were analyzed for three RFLPs (EcoRI, RsaI, and MspI) of the COL1A2 gene. Also, the same markers were studied in a population sample from Spain to compare the allele and haplotype frequencies of the Esmeraldas populations with those of their representative European parental population. Data for the native American and sub-Saharan African founder components were available from the literature. No significant levels of differentiation between the two African Ecuadoran communities emerged from either the frequency analysis of each single marker and all three RFLP markers together or from the AMOVA. The ladinos and mestizos also showed a rather similar distribution of allele and haplotype frequencies, confirming that the two ethnic terms do not correspond to genetically different populations. The comparison with the supposed founding European, sub-Saharan African, and native American populations indicated a large presence of African genes in the gene pool of both communities, with a higher proportion of the Amerindian component in Viche than in Rio Cayapas. The present findings confirm the previous genetic admixture estimates based on nuclear and mitochondrial DNA markers and the demographic data.
Assuntos
População Negra/genética , Colágeno Tipo I/genética , Etnicidade/genética , Genética Populacional/estatística & dados numéricos , Polimorfismo de Fragmento de Restrição , Alelos , Análise de Variância , Equador , Feminino , Frequência do Gene , Haplótipos , Humanos , Masculino , FenótipoRESUMO
É apresentada e discutida a casuística do Ambulatório de Genética da Faculdade de Ciências da Saúde da Universidade de Brasília, em seus quase 15 anos de existência. A partir de delineamento observacional descritivo seriado, apontam-se os procedimentos e instrumentos de coleta, registro e processamento de dados. As informações quantitativas apuradas, referentes a distribuições de freqüências absolutas e relativas, são apresentadas sob forma tabular corrente. As categorias identificadas de interesse para consideração foram sexo, faixa etária e proveniência dos probandos, motivo de consulta, motivo de encaminhamento, diagnóstico etiológico e produção acadêmica decorrente. Comparações são estabelecidas com resultados análogos anteriores dos autores, obtidos em experiências publicadas apropriadas a Serviços de Genética Clínica, destacadamente em universidades estaduais paulistas nos anos 70. Conclui-se pela aderência às recomendações de recente grupo técnico da Organização Mundial da Saúde
Assuntos
Pesquisa em Genética , Genética Populacional/estatística & dados numéricosRESUMO
Allele frequency data for the STR systems CSFaPO, TPOX, TH01, D13S317, D16S539, D5S818, and D7S820 were determined in a population sample of unrelated, healthy Amerindian Kichwa individuals. All loci met Hardy-Weinberg expectations, and there was no evidence for association of alleles among the seven loci.
Assuntos
Frequência do Gene , Variação Genética , Genética Populacional/estatística & dados numéricos , Indígenas Sul-Americanos/genética , Sequências de Repetição em Tandem , Alelos , Equador , Genótipo , Heterozigoto , HumanosRESUMO
BACKGROUND: The human malaria parasite Plasmodium falciparum expresses adhesins belonging to the erythrocyte membrane protein 1 (PfEMP1) family on the surface of the infected host erythrocyte. These antigens elicit a strain-specific antibody response that is associated with protection from disease. During clonal expansion of blood-stage parasites, the surface phenotype of the infected erythrocyte changes because of transcriptional switching among the 40 to 50 members of the highly polymorphic var multi-gene family which encode PfEMP1 variants. Studies to date have compared var repertoires of natural isolates from various geographical locations but have not addressed any within-population structure that may exist among repertoires. METHODS: Distinct parasite genotypes from a single population co-circulating among a defined group of hosts were selected. PCR products encoding the DBL-alpha domain of PfEMP-1 were cloned and sequenced from each of three isolates. Repertoire similarity was statistically evaluated using combinatorial analysis. The chromosomal location of shared sequences was inferred from similarity to dbl-alpha of known location in the 3D7 genome. RESULTS: Sympatric parasites were found to share few var gene sequences, even when alleles at other polymorphic loci were shared. A number of the sequences shared by at least two of the isolates studied were found to be related to 3D7 genomic sequences with non-telomeric chromosomal locations, or atypical domain structures, which may represent globally conserved loci. CONCLUSION: The parasite population studied is structured, with minimal overlap in PfEMP1 repertoires. The var gene family accumulates diversity more rapidly than other antigen genes examined. This may be facilitated by ectopic recombination among the sub-telomeric regions of P. falciparum chromosomes.
Assuntos
Genes de Protozoários , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Adolescente , Adulto , Animais , Antígenos de Protozoários/genética , Sequência Conservada/genética , Estudos Transversais , DNA de Protozoário/genética , Frequência do Gene/genética , Variação Genética , Genética Populacional/estatística & dados numéricos , Genótipo , Humanos , Malária Falciparum/epidemiologia , Masculino , Proteína 1 de Superfície de Merozoito/genética , Estrutura Terciária de Proteína/genética , Proteínas de Protozoários/genética , Venezuela/epidemiologiaRESUMO
The racial admixture of a target population can be ascertained by quantifying the contribution to the genetic pool of each of its components (ancestral populations), which could be two, three or more. The racial admixture is of importance for the understanding of results derived from biomedical and anthropological studies. The main objective of this investigation is to determine the population frequencies of genetic systems ABO and Rh and to use these data to calculate the racial admixture of the country and of each sample province, fitting a trihybrid model. To achieve this, the Krieger method, implemented by the computer program Mistura 3, was applied to phenotypic data of systems ABO and Rh in a sample of 4,202 subjects born in seven provinces. In the general population of Panama, 38.72% of genes from the genetic pool have an African origin, 35.87%, an Amerindian origin and 25.40%, a Caucasian origin. In the province of Cocle we found a contribution of 16.47% of African genes, 55.25% of Amerindian genes and 28.28% of Caucasian genes. The province of Colon presents 69.34% of African genes, 25.00% of Amerindian genes and 5.65% of Caucasian genes. In contrast, Chiriquí presents 5.56% of African genes, 50.63% of Amerindian genes and 43.80% of Caucasian genes. The province of Herrera is characterized by the following proportions: 58.45% African genes, 28.44% Amerindian genes and 13.11% Caucasian genes. In the province of Los Santos there is a 62.29% African contribution, a 14.35% Amerindian contribution and a 22.72% Caucasian one. In the province of Panama there is a 57.01%, 26.25% and 16.74% contribution of African, Amerindian and Caucasian genes, respectively. Finally, in Veraguas a contribution of 18.59% of African genes, 44.29% of Amerindian genes and 37.12% of Caucasian genes was found.