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- Review of the leaf-litter skinks (Scincidae: Panaspis) from the Gulf of Guinea Oceanic Islands, with the description of a new speciesPublication . Soares, Leonor B.; Ceríaco, Luis M. P.; Marques, Mariana P.; Bastos-Silveira, Cristiane; Scheinberg, Lauren A.; Harris, D. James; Brehm, António; Jesus, JoséLeaf-litter skinks of the genus Panaspis are currently represented in the oceanic islands of the Gulf of Guinea by two species, Panaspis africana and P. annobonensis. Here we describe a third species, Panaspis thomensis sp. nov., endemic to São Tomé Island. Data from previous studies and a new phylogenetic analysis using the mitochondrial 16S gene shows that the new species is genetically divergent and reciprocally monophyletic with respect to P. africana. Morphological data (scalation and morphometry) identify consistent, yet subtle, phenotypic differences between the two island populations. We also confirm that P. annobonensis represents a valid species, sister to the species pair P. africana + P. thomensis sp. nov., based on both molecular and morphological evidence. This description raises the number of known Panaspis species in the Gulf of Guinea oceanic islands to three, with consequences for the interpretation of local endemicity.
- Alpha-1-antitrypsin deficiency in the Cape Verde islands (Northwest Africa): high prevalence in a sub-Saharan populationPublication . Spínola, Carla; Brehm, António; Spínola, Hélder
- HLA-DQA1 and HLA-DQB1 allele diversity and its extended haplotypes in Madeira Island (Portugal)Publication . Spínola, H.; Lemos, A.; Couto, A. R.; Parreira, B.; Soares, M.; Dutra, I.; Bruges-Armas, J.; Brehm, A.This study shows, for the first time, high-resolution allele frequencies of HLA-DQA1 loci in Madeira Island (Portugal) and allows us to better understand and refine present knowledge on DQB1 variation, with the identification of several alleles not previously reported in this population. Estimates on haplotype profile, involving HLA-A, HLA-B, HLADRB1, HLA-DQA1 and HLA-DQB1, are also reported.
- Relationship between ADD1 Gly460Trp gene polymorphism and essential hypertension in Madeira IslandPublication . Sousa, Ana Célia; Palma dos Reis, Roberto; Pereira, Andreia; Borges, Sofia; Freitas, Ana Isabel; Guerra, Graça; Góis, Teresa; Rodrigues, Mariana; Henriques, Eva; Freitas, Sónia; Ornelas, Ilídio; Pereira, Décio; Brehm, António; Mendonça, Maria IsabelEssential hypertension (EH) is a complex disease in which physiological, environmental, and genetic factors are involved in its genesis. The genetic variant of the alpha-adducin gene (ADD1) has been described as a risk factor for EH, but with controversial results.The objective of this study was to evaluate the association of ADD1 (Gly460Trp) gene polymorphism with the EH risk in a population from Madeira Island.A case-control study with 1614 individuals of Caucasian origin was performed, including 817 individuals with EH and 797 controls. Cases and controls were matched for sex and age, by frequency-matching method. All participants collected blood for biochemical and genotypic analysis for the Gly460Trp polymorphism. We further investigated which variables were independently associated to EH, and, consequently, analyzed their interactions.In our study, we found a significant association between the ADD1 gene polymorphism and EH (odds ratio 2.484, P = .01). This association remained statistically significant after the multivariate analysis (odds ratio 2.548, P = .02).The ADD1 Gly460Trp gene polymorphism is significantly and independently associated with EH risk in our population. The knowledge of genetic polymorphisms associated with EH is of paramount importance because it leads to a better understanding of the etiology and pathophysiology of this pathology.
- Auto de entrega do corpo de D. Sebastião: Ceuta, 10 de dezembro de 1578Publication . Brehm, António Manuel Dias
- Distribution of polymorphisms IL4 -590 C/T and IL4 RP2 in the human populations of Madeira, Azores, Portugal, Cape Verde and Guinea-BissauPublication . Berenguer, Anabela G.; Câmara, Rita A.; Brehm, António D.; Oliveira, Susana; Fernandes, Ana T.The IL4 gene is located on chromosome 5q23.3-31.2. Polymorphisms within this cytokine gene, like the derivative allele T of IL4-590, have been reported as being associated to elevated IgE serum levels and asthma. In the present work, the allelic and genotypic frequency of the IL4-590 and IL4 RP2 polymorphisms was carried out in 599 individuals from Madeira, Azores, Portugal mainland, Cape Verde and Guinea-Bissau and in a sample of 101 asthmatics from Madeira population. In all populations the polymorphisms were in LD and presented a significant dissimilar allelic and genotypic distribution (p<0.05) except between mainland Portugal and Madeira when compared to Azores. Significant differences regarding both loci were found between Madeira population and the group of asthmatics. Genotype 183183TT frequency is higher for African populations while 253253CC prevails in Caucasian populations. The existence of a Hardy-Weinberg Disequilibrium in Guinea-Bissau population not observed in neutral markers leads to the hypothesis of natural selection occurring in these loci probably associated to a rapid population growth an hypothesis strengthened by neutral STRs D5S818 and CSF1PO gene diversity.
- Genetic risk analysis of coronary artery disease in a population based study in Portugal, using a genetic risk score of 31 variantsPublication . Pereira, Andreia; Mendonça, Maria Isabel; Borges, Sofia; Freitas, Sónia; Henriques, Eva; Rodrigues, Mariana; Freitas, Ana Isabel; Sousa, Ana Célia; Brehm, António; Reis, Roberto Palma dosBackground: Genetic risk score can quantify individual’s predisposition to coronary artery disease; however, its usefulness as an independent risk predictor remains inconclusive. Objective: To evaluate the incremental predictive value of a genetic risk score to traditional risk factors associated with coronary disease. Methods: Thirty-three genetic variants previously associated with coronary disease were analyzed in a case-control population with 2,888 individuals. A multiplicative genetic risk score was calculated and then divided into quartiles, with the 1st quartile as the reference class. Coronary risk was determined by logistic regression analysis. Then, a second logistic regression was performed with traditional risk factors and the last quartile of the genetic risk score. Based on this model, two ROC curves were constructed with and without the genetic score and compared by the Delong test. Statistical significance was considered when p values were less than 0.05. Results: The last quartile of the multiplicative genetic risk score revealed a significant increase in coronary artery disease risk (OR = 2.588; 95% CI: 2.090-3.204; p < 0.0001). The ROC curve based on traditional risk factors estimated an AUC of 0.72, which increased to 0.74 when the genetic risk score was added, revealing a better fit of the model (p < 0.0001). Conclusions: In conclusion, a multilocus genetic risk score was associated with an increased risk for coronary disease in our population. The usual model of traditional risk factors can be improved by incorporating genetic data.
- Colonization routes, microevolutionary genetic structure and conservation concerns in a remote widespread insular endemic grass: the case of the Azorean tussock grass Deschampsia foliosaPublication . Moura, Mónica; Catalán, Pilar; Brehm, António; Sequeira, Miguel Menezes dePopulation genetic structure and diversity and phylogeographical dispersal routes were assessed for the Azorean endemic grass Deschampsia foliosa using AFLP markers. This species occurs on seven islands in the archipelago and a sampling of populations from the three main geographical groups of islands was used, covering its known distribution. Principal coordinates analyses (PCoAs), Bayesian analyses and phylogenetic networks revealed different degrees of admixture for the central group (C) populations and a clear differentiation for the western group (W) and São Miguel island (in the eastern group, E) populations. The best K values corresponded to nine and 11 genetic groups, which were also confirmed by analysis of molecular variance. A low but significant correlation between genetic data and geography was observed, with most relevant barriers to gene flow generally placed between sub archipelagos. We suggest a west-to-east isolation by distance dispersal model across an island age continuum with Flores–Corvo (W) and Pico (C) at the extremes of the dispersal path. An alternative scenario, also supported by the genetic data, implies an initial colonization of São Jorge (C), dispersal within C and following bidirectional dispersal to the W and E. The phylogeographical framework detected might be related to island age and to highly destructive volcanic events, and it supports the occurrence of cryptic diversity within D. foliosa. Genetic diversity estimators were highest for Pico island populations (C), lowest for São Miguel (E) and Flores (W) populations, and more divergent for the Corvo population (W). Conservation measures should be taken to preserve the genetic structure found across sub-archipelagos and islands.
- Prevalence of H63D, S65C, and C282Y hereditary hemochromatosis gene variants in Madeira Island (Portugal)Publication . Spínola, Carla; Brehm, António; Spínola, HélderHereditary HFE Hemochromatosis is an inherited disorder of iron metabolism that results from mutations in the HFE gene. Almost all patients with hereditary hemochromatosis show a C282Y mutation in homozygosity or in compound heterozygosity with H63D. Also, the mutation S65C has been shown to be associated to a milder iron overload. Since allele and genotype frequencies of these three variants of the HFE gene vary between populations, the determination of their prevalence in Madeira Island will clarify the population susceptibility to hereditary hemochromatosis. One hundred and fifty-four samples from Madeira Island were genotyped for the three most common HFE gene mutations, H63D, C282Y, and S65C, by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results have shown a prevalence of 20.5%, 0.33%, and 1% for H63D, C282Y, and S65C, respectively. Accordingly to our estimates, both genotypes associated to hereditary hemochromatosis, C282Y homozygotes and C282/H63D compound heterozygotes, could be present in Madeira Island population in 1,648 individuals, which represents 0.65% of the total population.
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