[Show abstract][Hide abstract] ABSTRACT: SETTING: Cytokines play an important role in anti-tuberculosis immune response, combined with antigen-presenting cells and lymphocytes. Immune response gene polymorphisms have been reported to be associated with tuberculosis (TB) susceptibility in some but not all studies.OBJECTIVE: To evaluate the association of immune response genes with susceptibility to tuberculin skin test (TST) reactivity and/or TB.DESIGN: Fourteen single nucleotide polymorphisms were genotyped in 96 individuals of the Aché, a native Paraguayan population, by allelic discrimination using real-time polymerase chain reaction. Univariate and multivariate Poisson regression were employed to assess risk genotypes.RESULTS: A higher prevalence of purified protein derivative reactivity was associated with the TNF-α CCA/TCG haplotype (PR 1.298, 95%CI 1.059–1.589) and with the IL-10 AT/CC diplotype (PR 1.181, 95% CI 1.024–1.362), and the presence of the IL-8 rs4073 T allele was associated with protection against TB (PR 0.482, 95%CI 0.273–0.851).CONCLUSIONS: These results suggest that polymorphisms in genes associated with immune response are involved in TST reactivity and susceptibility to TB in the Aché population.
The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 08/2014; 18(8). · 2.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A general introduction to the origins and history of Latin American populations is followed by a systematic review of the data from molecular autosomal assessments of the ethnic/continental (European, African, Amerindian) ancestries for 24 Latin American countries or territories. The data surveyed are of varying quality but provide a general picture of the present constitution of these populations. A brief discussion about the applications of these results (admixture mapping) is also provided. Latin American populations can be viewed as natural experiments for the investigation of unique anthropological and epidemiological issues.
[Show abstract][Hide abstract] ABSTRACT: Lymphocyte cultures from 56 males of the Brazilian Ibagé breed, formed by crosses between Bos indicus and Bos taurus, reveal the co-existence of the acrocentric and submetacentric Y characteristic of Asian and European cattle respectively. The G and C bands support the hypothesis put forward previously that these two types of Y originated through a pericentric inversion. In one animal, one of the large autosomes (probably no. 6) was heteromorphic for the centromeric heterochromatin. The C bands of the Y in cattle are unusual; apparently contradictory results obtained by previous authors may be due to a peculiar sequence and composition of the nucleotides in the DNA of this chromosome in this organism.
Caryologia: International Journal of Cytology, Cytosystematics and Cytogenetics. 01/2014; 33(1):25-32.
[Show abstract][Hide abstract] ABSTRACT: The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N = 352; Baiano, N = 148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice.
PLoS ONE 01/2014; 9(5):e96886. · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Non-syndromic agenesis of permanent teeth is one of the most common anomalies in human development, a multifactorial characteristic caused by genetic and environmental factors. We describe a pair of monozygotic twins who showed second premolar and third molar agenesis, albeit with different expressions. We studied the DNA of two genes, paired domain box gene 9 (PAX9) and muscle segment homeodomain-homeobox1 (MSX1), encoding transcription factors that earlier studies found were involved in the manifestation of this condition. No specific causative mutation was found. However, we detected a C→T change in MSX1 exon 2 in both twins, suggesting that this polymorphism might be involved in the trait's expression.
Twin Research and Human Genetics 10/2013; · 1.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Native American populations generally have a higher prevalence of infectious diseases than non-Native populations and this fact can induce different pressures in their immune system. We investigated the patterns of population differentiation (FST ) of 32 polymorphisms related to adaptive immune response in four Native American populations (Aché, Guarani-Kaiowá, Guarani-Ñandeva and Kaingang), and the results were compared with the three major world population data [Yoruba of Ibadan, Nigeria (YRI), Utah residents with northern and Western Europe ancestry (CEU) and Han Chinese of Beijing, China (CHB)] available in the HapMap database. The Aché clearly differentiated from the other Amerindians, but when all Native Americans were compared with the samples of other ethnic groups the lowest difference (0.08) was found with CHB (Asians), the second lowest (0.15) with YRI (Africans) and the most marked with CEU (European-derived). The considerable intra and interethnic differences found can be explained both in terms of diverse evolutionary distances and more recent environmental pathogen exposures; and they should be appropriately considered prior to any specific public health action.
[Show abstract][Hide abstract] ABSTRACT: A total of 110 patients with severe (n = 43), moderate (n = 15) or mild (n = 52) haemophilia A were studied in relation to their F8 gene mutation and inhibitor status. Nineteen percentage of them had anti-factor VIII antibodies. Significant heterogeneity in inhibitor prevalence considering the location of the patients' mutation was found, with higher frequencies in carriers of mutations in the C1 and B domains. Twelve specific mutations showed associations with inhibitor formation, seven deletions, two nonsense, two insertions and one missense changes. Bioinformatic analysis of the missense mutation confirmed the formation of a B-cell epitope in the protein. This information is important for comparative purposes with series of other ethnic constitutions, as well as for individual prevention of this serious clinical problem in the patient population.
Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 08/2013; · 1.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A total of 76 unrelated male patients with mild (n = 55) or moderate (n = 21) haemophilia A living in the southern Brazilian state of Rio Grande do Sul were studied by direct sequencing of all F8 26 exons, the 5' UTR and 3' UTR, intron-exon junctions and the promoter region. When no mutation was found, a Multiplex ligation-dependent probe amplification analysis was performed. We identified the disease-causing mutations in 69 patients, who showed 33 different mutations: 27 missense, one small deletion, two small duplications and three splice site mutations. Seven missense and two splice site mutations were not previously reported in HAMSTeRS and were not identified in any current literature search. Nine recurrent mutations were found, one of them never described before (p.Tyr1786Phe). Haplotype analysis indicated that this mutation had originated in the Brazilian population as a single event in a common ancestor. The possible influence of these mutations in the determination of the disease was carefully considered, including bioinformatic tools. These data add to the general knowledge of the disease and can also be useful for HA diagnosis and detection of carriers in the southern Brazilian population.
[Show abstract][Hide abstract] ABSTRACT: The relationship between the "individualism-collectivism" and the serotonin trans-porter functional polymorphism (5-HTTLPR), suggested in the previous reports, was tested in Native South Amerindian populations. A total of 170 individuals from 21 populations were genotyped for the 5-HTTLPR alleles. For comparative purposes, these populations were classified as individualistic (recent history of hunter–gathering) or collectivistic (agriculturalists). These two groups showed an almost identical S allele frequency (75 and 76%, respectively). The analysis of molecular variance showed no structural differences between them. Behavioral typologies like those sug-gested by JY Chiao and KD Blizinsky (Proc R Soc B 277 (2010) 529–537) are always a simplification of complex phenomena and should be regarded with caution. In addition, classification of a whole nation in the individu-alist/collectivist dichotomy is controversial. The focus on modes of subsistence in preindustrial societies, as was tested here, may be a good alternative although the postulated association between the 5-HTTLPR S allele and the collectivist societies was not confirmed. Am J Phys Anthropol 000:000–000, 2013. V C 2013 Wiley Periodicals, Inc.
American Journal of Physical Anthropology 05/2013; · 2.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The relationship between the evolution of genes and languages has been studied for over three decades. These studies rely on the assumption that languages, as many other cultural traits, evolve in a gene-like manner, accumulating heritable diversity through time and being subjected to evolutionary mechanisms of change. In the present work we used genetic data to evaluate South American linguistic classifications. We compared discordant models of language classifications to the current Native American genome-wide variation using realistic demographic models analyzed under an Approximate Bayesian Computation (ABC) framework. Data on 381 STRs spread along the autosomes were gathered from the literature for populations representing the five main South Amerindian linguistic groups: Andean, Arawakan, Chibchan-Paezan, Macro-Jê, and Tupí. The results indicated a higher posterior probability for the classification proposed by J.H. Greenberg in 1987, although L. Campbell's 1997 classification cannot be ruled out. Based on Greenberg's classification, it was possible to date the time of Tupí-Arawakan divergence (2.8 kya), and the time of emergence of the structure between present day major language groups in South America (3.1 kya).
PLoS ONE 05/2013; 8(5):e64099. · 3.73 Impact Factor