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Objective: The short-term impact of the pre-symptomatic genetic test (PT) for Machado-Joseph disease (MJD) in the Azores (Portuguese Islands) was assessed in 46 individuals at risk who completed the PT Program. Methods: Scores for depression and anxiety were used as indicators of the subjects’ emotional status immediately before the PT and 1 year after disclosure of the results. Results: Global levels of participation in the Azorean PT Program for MJD were high (20.7%), particularly in Flores Island (35.8%). For the total sample, mean scores of depression and anxiety before and after the PT presented without clinical significance. No differences were found for depression and anxiety scores before and after the PT. Furthermore, when grouped by test results (carriers/non-carriers), there were no differences between pre- and post-test levels. Conclusions: Results indicate that the test result did not cause a decrease in the psychological well-being of the individuals tested. The high number of participants performing the PT in the small and isolated community of Flores Island, where MJD represents a source of stigma, was interpreted as an indication that in this particular population the PT offers the individuals at risk the possibility of liberating from a stigma, and, hence, from exclusion.Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This study evaluated the concentrations of α-tocopherol, β-carotene, creatine, carnosine, anserine and coenzyme Q10 in Longissimus dorsi (Ld) and Gluteus medius (Gm) muscles of culled dairy cows and the impact of age, production status before slaughter (dry-off vs lactating) and carcass weight on them. The effects of applying a finishing feeding regimen before slaughter were also examined. Gm muscle presented higher levels (P<0.001) of α-tocopherol (5.14 vs 3.61 μg · g(-1)) β-carotene (0.36 vs 0.27 μg · g(-1)), anserine (59.24 vs 43.25 mg · 100 g(-1)) and coenzyme Q10 (3.33 vs 1.73 mg · 100 g(-1)), and by contrast lower (P<0.05) creatine concentration (502.40 vs 527.28 mg · 100 g(-1)) than Ld. Dry-off and lactating cows differed significantly in α-tocopherol level (P<0.001) but not in the concentrations of the other compounds (P>0.05). The finishing feeding promoted higher mean concentrations of anserine and creatine but lower carnosine values (P>0.05) than directly slaughtered dry-off cows. The variation between muscles and from animal-to-animal makes it difficult to exactly define the antioxidant status of the dairy cow's meat., (© 2013.)

Background: Atherosclerosis-a major cause of vascular disease, including ischemic heart disease (IHD), is a pathology that has a two-fold higher mortality rate in the Azorean Islands compared to mainland Portugal., Aim: This cross-sectional study investigated the role of genetic variation in the prevalence of atherosclerosis in this population., Subjects and Methods: A total of 305 individuals were characterized for polymorphisms in eight susceptibility genes for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1 and APOE. Data were analysed with respect to phenotypic characteristics such as blood pressure, lipid profile, life-style risk factors and familial history of myocardial infarction., Results: In the total sample, frequencies for hypercholestrolemic, hypertensive and obese individuals were 63.6%, 39.3% and 23.3%, respectively. The genetic profile was similar to that observed in other European populations, namely in mainland Portugal. No over-representation of risk alleles was evidenced in this sample., Conclusions: One has to consider the possibility of an important non-genetic influence on the high cholesterolemia present in the Azorean population. Since diet is the most important life-style risk factor for dyslipidemia, studies aiming to evaluate the dietary characteristics of this population and its impact on serum lipid levels will be of major importance.

Macaronesia covers four Atlantic archipelagos: the Azores, Madeira, the Canary Islands, and the Cape Verde islands. When discovered by Europeans in the 15th century, only the Canaries were inhabited. Historical reports highlight the impact of Iberians on settlement in Macaronesia. Although important differences in their settlement are documented, its influence on their genetic structures and relationships has yet to be ascertained. In this study, the hypervariable region I (HVRI) sequence and coding region polymorphisms of mitochondrial DNA (mtDNA) in 623 individuals from the Azores (120) and Canary Islands (503) were analyzed. Combined with published data, these give a total of 1,542 haplotypes from Macaronesia and 1,067 from the Iberian Peninsula. The results obtained indicate that Cape Verde is the most distinctive archipelago, with an mtDNA pool composed almost exclusively of African lineages. However, the other archipelagos present an mtDNA profile dominated by the presence of West-Eurasian mtDNA haplogroups with African lineages present in varying proportions. Moreover, no signs of integration of typical Canarian U6 lineages in the other archipelagos were detected. The four Macaronesia archipelagos currently have differentiated genetic profiles, and the Azores present the highest intra-archipelago differentiation and the lowest values of diversity. The analyses performed show that the present-day genetic profile of the Macaronesian archipelagos was mainly determined by the initial process of settlement and further microdifferentiation probably as a consequence of the small population size of some islands. Moreover, contacts between archipelagos seem to have had a low impact on the mtDNA genetic pool of each archipelago., ((c) 2009 Wiley-Liss, Inc.)

The populations from the Azores islands have been the target of several genetic studies, using data derived from monoparental and recombining genetic systems. These studies have provided a complex picture of the genetic landscape of the three groups of Azorean islands, and further data are required to assess its genetic profile. We present a study of the polymorphism in 10 X-chromosome STR loci (DSXS8378, DXS9898, DXS7133, GATA31E08, GATA172D05, DXS7423, DXS6809, DXS7132, DXS9902, DXS6789) conducted on a total of 304 chromosomes (97 females and 110 males) of unrelated individuals with Azorean ancestry. Average gene diversity was 74.47%, ranging from 66.21% (DXS7133) to 81.19% (GATA172D05). No shared haplotypes were found. Genotype frequencies among females displayed conformity with Hardy-Weinberg expectations for all loci. Pairwise linkage disequilibrium tests did not reveal evidences of association between the studied markers. Significant differences in allelic frequencies between the Western and the Eastern group of islands are in agreement with previous results from mitochondrial DNA and Y chromosome studies, providing further evidence that the Azores cannot be considered an homogeneous population. Moreover, differences between the Western group and the North of Portugal are also reported, supporting the pertinence of a specific database for the Azores populations, on what concerns the genetic markers analyzed., ((c) 2009 Wiley-Liss, Inc.)

The Azores archipelago (Portugal), located in the Atlantic Ocean, 1,500 km from the European mainland, is formed by nine islands of volcanic origin. The relative position of these islands allows the definition of three geographical groups: Eastern, Central and Western. Previous studies of the Azores using Short Tandem Repeats (STRs) have highlighted differences in the frequencies of several loci, when compared to Mainland Portugal or Madleira Island. Furthermore, linkage disequilibrium (LD), described for Azorean samples has been tentatively explained as reflecting the presence of genetic sub-structuring in the archipelago. To provide information concerning the genetic profile of the Azores Islands and to evaluate the presence of substructuring we have determined the allelic frequencies of 15 autosomal STR loci, using the AmpFlSTR Identifiler Kit, in representative samples from the Azorean Islands. Either considering the Azores as a whole, or analysing by island all the loci were in conformity with Hardy-Weinberg equilibrium. Average gene diversity ranged from 0.7669 in Corvo to 0.7972 in Terceira Island. Allelic independence between loci, tested for the global sample, detected significant LD (after correction for multiple tests) for pairs D21S11/D7S820 and D3S1358/D5S818. The exact test of population differentiation, combining the information of the 15 markers analysed, revealed significant differences between the three groups of islands, and between islands. Inter-island analysis reinforces the previous data that suggested the existence of sub-structuring in the Azores archipelago. Moreover, the data generated by this study can be used in a future forensic genetic database of the Azores after the appropriate enlacement of sample size by island, preventing, in that way, misinterpretations caused by population substructuring and small sample sizes.

The Azores archipelago (Portugal) is formed by nine islands whose relative positions define them as three geographical groups: Eastern (S. Miguel and Sta. Maria), Central (Terceira, Faial, Pico, Graciosa and S. Jorge) and Western (Flores and Corvo). Using the father's surname of 187,398 individuals living on the nine Azorean Islands, a population analysis based on inter-island relationship and hierarchical organization was conducted. The relation between islands was investigated using summary statistics, analysis of molecular variance (AMOVA) as well as graphical methods. When the values of heteronymy were contrasted with values of gene diversity based on haplogroup frequencies of the Y chromosome, it was possible to verify that Graciosa and Sta. Maria appeared to have the least diverse populations, and that Flores, despite its smaller population size and geographical isolation, has considerably higher levels of diversity. As for inter-island relationships, the difficulty of directly interpreting summary statistics values was evidenced. The AMOVA revealed that only 0.77% of the variation in surnames can be attributed to among-island variation, a value that, although small, can be considered significant. Application of Malécot's model revealed that geographic distance has an important impact in the genetic structure of the archipelago. Monmonier's maximum-difference algorithm demonstrated that the most isolated island of the archipelago appears to be Graciosa, followed by the islands of the Western group and by Sta. Maria. After integrating values of summary statistics with results from AMOVA and graphical methods, a more accurate genetic profile of the Azores, highly supported by genetic data, has emerged.

Background: Human mitochondrial DNA (mtDNA) has been extensively used in population and evolutionary genetics studies. Thus, a valid estimate of human mtDNA evolutionary rate is important in many research fields. The small number of estimations performed for the coding region of the molecule, showed important differences between phylogenetic and empirical approaches. We analyzed a portion of the coding region of mtDNA (tRNALeu, ND1 and tRNAIle genes), using individuals belonging to extended families from the Azores Islands (Portugal) with the main aim of providing empirical estimations of the mutation rate of the coding region of mtDNA under different assumptions, and hence to better understand the mtDNA evolutionary process., Results: Heteroplasmy was detected in 6.5% (3/46) of the families analyzed. In all of the families the presence of mtDNA heteroplasmy resulted from three new point mutations, and no cases of insertions or deletions were identified. Major differences were found in the proportion and type of heteroplasmy found in the genes studied when compared to those obtained in a previous report for the D-loop. Our empirical estimation of mtDNA coding region mutation rate, calculated taking into account the sex of individuals carrying new mutations, the probability of intra-individual fixation of mutations present in heteroplasmy and, to the possible extent, the effect of selection, is similar to that obtained using phylogenetic approaches., Conclusion: Based on our results, the discrepancy previously reported between the human mtDNA coding region mutation rates observed along evolutionary timescales and estimations obtained using family pedigrees can be resolved when correcting for the previously cited factors.

Machado-Joseph disease (MJD) is caused by an expansion of a triplet repeat with a CAG motif at the ATXN3 gene. The putative segregation ratio distortion (SRD) of alleles can play an important role in the non-Mendelian behaviour of triplet repeat loci. To study the stability and infer the segregation patterns of wild-type MJD alleles, the size of the (CAG)(n) tract was analysed in 102 normal sibships, representing 428 meioses. No mutational events were detected during the transmission of alleles. Segregation analysis showed that the smaller alleles were preferentially transmitted (56.9%). Considering maternal meioses alone, such preference was still detected (55.7%) but without statistical significance. A positive correlation was observed for the difference in length between the two alleles constituting the transmitters' genotype (D) and the frequency of transmission of the smaller alleles. The results suggest that small D values are not enough to modify the probability of allele transmission. When transmissions involving genotypes with D

Among the settlers that, from 1432 onwards, arrived to the Azores Islands were individuals of North and sub-Saharan African origin. A previous study of markers of the Y chromosome revealed that haplogroup E is the second more frequent in the Azores (13%). Since this haplogroup is heterogeneous and may contain subtypes of African or non-African origin, we analyzed an extended sample of 319 Azoreans, originating from the three groups of islands (Eastern, Central, and Western), to evaluate the African contribution to the present-day population of the Azores. Samples belonging to the E clade were distributed into six haplogroups, from which the most frequent was E3b1a, representing 47.2% of the E chromosomes (6.3% of the total sample). The sub-Saharan haplogroup E3a was found in 7.1% of E chromosomes (0.9% of the total), corresponding to the highest frequency reported so far in a Portuguese population. No significant differences were detected in the haplogroup distribution among groups of islands, as well as between Azores and most of other European populations compared. The present-day representation of sub-Saharan lineages in Azores, although reduced, is higher than in other Portuguese populations, where the demographic representation of sub-Saharan slaves is reported as similar., (Copyright 2007 Wiley-Liss, Inc.)

Our aim in this study is to report on the polymorphism of the APOE gene in the Azores Islands (Portugal) to obtain a population baseline of the existing variation in this locus, known to be one of the genetic determinants of plasma lipid levels. One hundred twenty-six Azorean individuals were typed for the APOE polymorphism using standard PCR-RFLP. Allele frequencies obtained for APOE*2, APOE*3, and APOE*4 were 6.75%, 83.73%, and 9.52%, respectively. The APOE*3/*3 genotype presented the highest frequency (69.84%), and the APOE*4/*4 genotype had the lowest frequency (0.79%). Genotype frequencies were in conformity with Hardy-Weinberg expectations. The observed genotype and allele frequencies were similar to those reported for other Iberian samples. Furthermore, Nei's gene diversity (H = 0.2864 +/- 0.0351) was similar to that reported for samples from mainland Portugal. The data generated from this study will be of importance in the context of ongoing studies concerning the factors that influence lipid levels in the Azorean population.

We analyzed the control region of the mitochondrial DNA (mtDNA) from maternally related individuals originating from the Azores Islands (Portugal) in order to estimate the mutation rate of mtDNA and to gain insights into the process by which a new mutation arises and segregates into heteroplasmy. Length and/or point heteroplasmies were found at least in one individual of 72% of the studied families. Eleven new point substitutions were found, all of them in heteroplasmy, from which five appear to be somatic mutations and six can be considered germinal, evidencing the high frequency of somatic mutations in mtDNA in healthy young individuals. Different values of the mutation rate according to different assumptions were estimated. When considering all the germinal mutations, the value of the mutation rate obtained is one of the highest reported so far in family studies. However, when corrected for gender (assuming that the mutations present in men have the same evolutionary weight of somatic mutations because they will inevitably be lost) and for the probability of intraindividual fixation, the value for the mutation rate obtained for HVRI and HVRII (0.2415 mutations/site/Myr) was in the upper end of the values provided by phylogenetic estimations. These results indicate that the discrepancy, that has been reported previously, between the human mtDNA mutation rates observed along evolutionary timescales and the estimations obtained using family pedigrees can be minimized when corrections for gender proportions in newborn individuals and for the probability of intraindividual fixation are introduced. The analyses performed support the hypothesis that (1) in a constant, tight bottleneck genetic drift alone can explain different patterns of heteroplasmy segregation and (2) in neutral conditions, the destiny of a new mutation is strictly related to the initial proportion of the new variant. Another important point arising from the data obtained is that, even in the absence of a paternal contribution of mtDNA, recombination may occur between mtDNA molecules present in an individual, which is only observable if it occurs between mtDNA types that differ at two or more positions.

The island of Flores is the most westerly of the Azores archipelago (Portugal). Despite its marked geographic isolation and reduced population size, biodemographic and genetic studies conducted so far do not support the idea that its population constitutes a genetic isolate. In this study we conducted a surname analysis of the Flores population for two time periods: the second half of the 19th century and the present day. Our main purposes were (1) to biodemographically and genetically characterize the island, taking into account the strong reduction in population observed from the middle of the 19th century to the present day; and (2) to analyze the influence that the effective population size and geographic distance have on the genetic structure of populations. For both periods analyzed, all indicators of diversity revealed a high level of surname diversity. Our results are in accordance with the diversity estimates obtained from both monoparental genetic markers located in the Y chromosome and frequencies of mtDNA haplogroups. Contrary to what could be expected, considering the strong reduction of population in the last 150 years, we observed that diversity was maintained and that microdifferentiation decreased. Both observations support a higher openness of parishes as a consequence of the increase in communication routes. From the first to the second period analyzed, a change in surname composition is evident, although the more frequent surnames in Flores are almost the same for both periods and some of them are reported to be surnames present in the first settlers of Flores. This result testifies to the impact of founders on the present-day gene pool of Flores island and allows us to infer that the genetic characterization of the present-day population of Flores could provide reliable information about the history of the peopling of the Azores.

In this paper we propose a hierarchical approach that allows the screening of mitochondrial DNA (mtDNA) haplogroups in populations that have essentially West Eurasian mtDNA backgrounds but that could have some non-West Eurasian contributions. To develop and validate this scheme, we used data on 18 coding region polymorphisms (17 analyzed by RFLP analysis and 1 by sequencing) and sequences of hypervariable segment I (HVSI) of the mtDNA control region from the Azores Islands (Portugal) population. The proposed scheme allows the characterization of almost all West Eurasian and African major clusters by means of RFLPs. Furthermore, the scheme includes information on situations in which sequencing is pertinent to defining a particular haplogroup. The validity of the scheme is ensured by (1) using relatively stable polymorphic positions, (2) screening more than one position to define a specific haplogroup, and (3) typing confirmatory positions. Dubious samples can be resolved by sequencing. The robustness of this approach was assessed by sequencing all samples for HVSI, taking advantage of the previously established relationships between RFLPs and control region sequence polymorphisms. The use of this hierarchical approach avoids the screening of unnecessary control region polymorphisms and therefore results in a more rapid and cost-efficient screening than one in which all polymorphic positions are analyzed. Even if this approach leads to a lower level of phylogeographic resolution than the sequencing of all samples, it allows us to define population movements on a continental level and can be applied, unlike sequencing all samples, with a low cost in any laboratory.

Objective: The short-term impact of the pre-symptomatic genetic test (PT) for Machado-Joseph disease (MJD) in the Azores (Portuguese Islands) was assessed in 46 individuals at risk who completed the PT Program., Methods: Scores for depression and anxiety were used as indicators of the subjects' emotional status immediately before the PT and 1 year after disclosure of the results., Results: Global levels of participation in the Azorean PT Program for MJD were high (20.7%), particularly in Flores Island (35.8%). For the total sample, mean scores of depression and anxiety before and after the PT presented without clinical significance. No differences were found for depression and anxiety scores before and after the PT. Furthermore, when grouped by test results (carriers/non-carriers), there were no differences between pre- and post-test levels., Conclusions: Results indicate that the test result did not cause a decrease in the psychological well-being of the individuals tested. The high number of participants performing the PT in the small and isolated community of Flores Island, where MJD represents a source of stigma, was interpreted as an indication that in this particular population the PT offers the individuals at risk the possibility of liberating from a stigma, and, hence, from exclusion.

The Azores islands (Portugal), uninhabited when discovered by Portuguese navigators in the fifteenth century, are located in the Atlantic Ocean 1500 km from the European mainland. The archipelago is formed by nine islands of volcanic origin that define three geographical groups: Eastern (S. Miguel and Sta. Maria), Central (Terceira, Faial, Pico, Graciosa and S. Jorge) and Western (Flores and Corvo). To improve the genetic characterisation of the Azorean population, and to clarify some aspects related to the history of settlement, a study of mtDNA was conducted in the population of the archipelago. The HVRI region was sequenced and specific RFLPs were screened in 146 samples obtained from unrelated individuals with Azorean ancestry (50 from the Eastern group, 60 from the Central group, and 37 from the Western group). Samples were classified into haplogroups based on the information obtained from both sequencing and RFLP analysis. All the analyses performed support the idea that, in the whole group of islands, the majority of mtDNA lineages originated from the Iberian Peninsula, mainly from Portugal (mainland). However contributions from other European populations, especially from Northern Europe, cannot be disregarded. The values obtained for the various diversity parameters in the Azores archipelago indicate that the Azorean population, as a whole, does not exhibit the typical characteristics of an isolated population. The analysis of genetic data by groups of islands showed that the Western group exhibited particular features. The distribution of haplogroups in the Western group is very atypical, being significantly different from what is observed in the Eastern and Central groups. Furthermore, the diversity values are, in general, lower than those observed in other populations used for comparison. African haplogroups were found in all the groups of islands. Therefore the presence of Moorish and African slaves on the islands, as reported in historical sources, is supported by the mtDNA genetic data, especially in the Eastern group. The presence of Jews in the Central group is also supported by the mtDNA data. Neither historical nor genetic data (phylogeography of mtDNA) supports the idea of a differential settlement history for the Western group; however, it is represented in the phylogenies as an isolated branch. The effect of genetic drift, induced by the reduced population size since peopling occurred, has led to a very atypical distribution of haplogroups/haplotypes in this group of islands. We cannot ignore the influence of biodemographic and genetic processes, namely founder effect, genetic drift, migration, and even recent mutational events in the mtDNA lineages of the Azorean populations. Nevertheless, a great part of the variation in the Azorean mtDNA can be explained by the settlement history.