Augusto Abade's research while affiliated with University of Coimbra and other places

Publications (43)

Article
Three major loci have been associated with HbF levels, including -158C/T (XmnI) at HBG2 promoter region, and several polymorphisms at BCL11A intron-2 and HBS1L-MYB (HMIP) intergenic region. Mutations in the KLF1 gene were recently associated with increased HbF levels. This study aims to evaluate whether genetic variability at these loci influences...
Article
The genetic diversity of human populations in Portugal results from several different demographic events that occurred in distinct prehistorical and historical periods. The main objective of this study was to examine if patterns of Y-chromosome diversity explained by ancient maritime Mediterranean expansions can be observed in Coimbra district (cen...
Article
Background: The - 13910C>T polymorphism has been associated with lactase persistence (LP) in European populations. Aim: To assess - 13910C>T genotypes across Portugal and in adult individuals with unspecific gastrointestinal complaints associated with milk consumption. Subjects and methods: This study genotyped - 13910C>T in the general popula...
Article
Allele frequencies of six autosomal short tandem repeat (STR) markers (TH01, TPOX, CSF1PO, D13S317, D7S820 and D16S539) were estimated in a population sample (N=53-85) of unrelated individuals from São Tomé e Principe (West Africa). No deviations from Hardy-Weinberg equilibrium were observed for all loci. Allele frequency distribution and heterozyg...
Article
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 a...
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G6PD deficiency mutational profile and haplotype diversity using 6 RFLPs (FokI/PvuII/BspHI/PstI/BclI/NlaIII) and a (CTT)(n) microsatellite, were investigated in 70 G6PD-deficient Portuguese individuals. All but one G6PD A-(376G/202A) variants (44/45) have a single haplotype (+/+/-/+/-/+/195). G6PD Betica(376G/968C) alleles (n=10) have a single RFLP...
Article
A population sample from São Tomé e Príncipe (West Africa) was screened for the G6PD-deficient variants A- (376G/202A), Betica (376G/968C), and Santa Maria (376G/542T). G6PD locus haplotype diversity was also investigated using six intragenic RFLPs (FokI, PvuII, BspHI, PstI, BclI, NlaIII) and a (CTT)n microsatellite 18.61 kb within the G6PD locus....
Article
Twenty biallelic Y chromosome markers were analyzed in Angolares, Forros and Tongas, three population groups from the African archipelago of São Tomé e Príncipe. While most male lineages belonged to sub-Saharan haplogroups, the component of European origin added up 23.9% in the archipelago. This contrasts with the reported absence of European mtDNA...
Article
We have conducted studies to assess the variability of mtDNA and Y-chromosome markers in the Azores Islands (Portugal) and found that, for both genetic systems, the Azores, as a whole, fit well into the pattern of variation described for other Western European populations. Phylogeographic analysis of mitochondrial DNA (mtDNA) showed a major contrib...
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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 lea...
Article
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...
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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 an...
Article
Sequence data from the hypervariable segments I (HVS-I) and II (HVS-II) was obtained for 30 Angolares, 35 Forros and 38 Tongas, three self-reported ethnic groups from São Tomé e Prı́ncipe, an African archipelago (Gulf of Guinea) whose settlement begun in the late 15th century. The repertory of mtDNA lineages denoted a fully African maternal pool pr...
Article
We have analysed the matrilineal genetic composition of three self-reported ethnic groups from São Tomé e Príncipe (Gulf of Guinea), an African archipelago whose settlement begun in the late fifteenth century. Sequence data from the hypervariable segments I (HVS-I) and II (HVS-II) were obtained for 30 Angolares, 35 Forros and 38 Tongas. The reperto...
Article
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L¿archipel des Açores (Portugal) est situé dans l¿Océan Atlantique à 1500 Km du Portugal continental. Il est formé par neuf îles d¿origine volcanique qui forment trois groupes: Oriental, Central et Occidental. L¿île de Flores, la plus occidentale et isolée de l¿archipel, présente des caractéristiques géographiques et démographiques uniques et elle...
Article
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, Gr...
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Full-text available
Machado-Joseph Disease (MJD) is an autosomal dominant neurodegenerative disorder of adult onset, associated with the expansion of a (CAG)n tract in the coding region of the causative gene, localized on 14q32.1. Machado-Joseph Disease shows non-Mendelian features typical of other triplet repeat disorders, including clinical heterogeneity, variable a...
Article
Four intragenic PKLR polymorphisms [1705A/C, 1738C/T. T10/19, and (ATT)n microsatellite] were studied in normal population samples of Central Portugal and São Tomé e Príncipe, a small archipelago located in the Gulf of Guinea, West Africa. For all loci, the observed genotype distributions do not deviate from Hardy-Weinberg equilibrium. The allele f...
Article
Seven Y-chromosome STR loci, DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393 have been analysed in population samples of Angolares, Forros and Tongas, three ethnic groups from the African archipelago of São Tomé e Príncipe (Gulf of Guinea). Complete typings were obtained for 103 chromosomes, which belonged to 79 different haplotypes. Th...
Article
Machado-Joseph disease (MJD) reaches its highest prevalence world-wide in the Azores, thus constituting a public health problem in these islands. The aim of the study was thus to (1) determine the level of knowledge about the disease; (2) estimate the expected level of request for predictive testing, and (3) analyse the intentions of at-risk indivi...
Article
A great deal of research as been directed towards understanding the genetics of HLA. Because humans are exposed to a great number of genetically different parasites, which can impose large selective costs, it is important for the HLA to be as diverse as possible so that the immune system can recognise and control as many of these as possible. Conse...
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The distribution of phenotypes of the red cell esterase D (ESD), glyoxalase 1 (GLO1), glutamate pyruvate transaminase (GPT) and phosphoglucomutase 1 (PGM1) were analysed by starch gel electrophoresis in unrelated native-born residents in Sao Tome and Principe, for the purpose of genetic characterization of this population. The allele frequencies fo...
Article
Full-text available
Mutations in the PKLR gene responsible for pyruvate kinase (PK)-deficient anaemia are mainly located in the coding regions: 11 are in the splicing sites and, recently, three mutations have been described in the promoter region. We now report a novel point mutation A-->G on nucleotide 72, upstream from the initiation codon of the PKLR gene, in four...
Article
Full-text available
The genetic polymorphism of AMY2 was studied in the population of S. Tomé and Príncipe (West Africa) using agarose gel electrophoresis. AMY2 frequencies are reported for the first time in a subSaharian population. The gene frequencies found were: AMY2*1=0.948, AMY2*3=0.052 (N=173).
Article
In nine unrelated Portuguese patients with pyruvate kinase (PK) deficient anaemia, whose symptoms ranged from a mild chronic haemolytic anaemia to a severe anaemia presenting at birth and requiring multiple transfusions, the PK-LR gene mutations were identified and correlated with their phenotypes. Five different mutations were identified, three of...
Article
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder of adult onset. In the islands of the Azores (Portugal), MJD reaches the highest prevalence reported worldwide. It has been postulated that it is highly represented in the Azorean population as a result of a founder effect. To test this hypothesis, we reconstructed the...
Article
Machado-Joseph disease (MJD) is an autosomal dominant cerebellar ataxia of adult onset with a high prevalence in the islands of Azores (Portugal). The genetic epidemiological studies presently under way in these islands are based on the genealogical reconstruction of the affected families, thus partially depending on the reference of patients using...
Article
The hypervariable segment I of the control region of the mtDNA was sequenced in 45 unrelated individuals from Bioko and 50 from São Tomé, two islands in the Gulf of Guinea that have had very different settlement patterns: Bioko was colonized around 10000 BP, while São Tomé was first settled by the Portuguese, who brought African slaves to the islan...
Article
Machado-Joseph disease (MJD) is an autosomal, dominantly inherited neurodegenerative disorder of adult onset. The prevalence of MJD reaches its highest values in the islands of the Azores. A research program was undertaken to study the origin and spread of the mutant gene in the Azorean populations. Here, we present the first results of such a stud...
Article
In populations in which the frequency of illegitimacy is high, illegitimates and legitimates may be subjected to different demographic and social pressures, with social and genetic consequences. A rural population from north-east Portugal is studied and variables from birth, marriage and death records are compared according to the legitimacy of the...
Article
From marriage records of a Northern Portuguese parish for 1900-80, endogamy and exogamy rates were calculated for birthplace and residence in order to analyse the effect of industrialisation on the population structure after 1940. Marriages that were endogamous relative to birthplace decreased between 1940-49 (58.9%) and 1988 (20.5%), while exogamy...
Article
Flores is one of the smallest and most westerly islands of the Atlantic archipelago of the Azores. This preliminary account of the population's demography and genetic structure uses dispensations to contract consanguineous marriages taken from the Roman Catholic marriage registers in order to estimate mean inbreeding rates in the population over th...

Citations

... With respect to development patterns, when these subadults were compared to the skeletal growth profile of the CISC, constructed on the basis of femur diaphyseal length (Cunha et al., 1999), it became clear that both individuals were taller than an average 11-yearold child. This was particularly true for the SCV 2. The morphological evaluation of these skeletons for sex was inconclusive. ...
... This is because of their potential use in developing targeted therapeutic approaches for β-thalassemia, γ-globin, and Hb switching modifier genes [17]. Individuals who have severe hemoglobinopathies caused by βglobin chain disorders, such as β-thalassemia intermedia and major, typically, clinical phenotypes are inversely related to the degree of HbF expression retention [18]. The results of ARMS PCR analysis for the BCL11A gene showed that three genotypes, AA, AC, and CC were in βthalassemia major patients' samples with frequencies of 0.3, 0.6, and 0.1, respectively, and in control 0.1, 0.8, and 0.1, respectively. ...
... Other E1b1b subhaplogroups have a similar frequency in Africa and Europe (E1b1b-M78), with a high prevalence in North Africa, and in the Iberian Peninsula (E1b1b-M81) and in West Asia and Europe (E1b1b-M123) 41 . We believe that this higher frequency of E1b1b is due to the Portuguese influence in our population, since in a study conducted by Martiniano et al., E1b1b had the third-highest frequency (12.0%) in the studied Portuguese population 38 . ...
... For comparison purposes, and as there are few studies regarding African population for mtDNA total control region, the sequences of the studied population were reduced to HVI and HVII regions, to allow comparison with other populations studied for HVI and HVII regions. In this case, the population of Angolan immigrants living in Lisboa was compared with populations from Guinea Bissau [29], Cape Verde [33], Somalia [31], Ghana [32], Mozambique [38], S. Tome and Principe [48], Angola [42], indigenous Khoe-san [37], Bantu ethnic groups from Angola [35,36] and Cabinda [34], all of them with sequenced HVI and HVII regions (Table 3) (Fig. 2). These results culminate in a short distance between the population of Angolan immigrants living in Lisboa and Angolan, people living in Angola as well Bantu ethnic groups from Angola, giving information that the first one maintains the genetic information of its origin, although, nowadays, inhabiting a different geographic region. ...
... To better understand the genetic basis of metabolic syndrome, it is important to replicate association evaluations in independent studies worldwide. Indeed, previous studies [24][25] showed that T allele frequency is not uniform across the literature, varying from 0.269 until 0.402. Our results are slightly higher than those reported in these studies. ...
... As a consequence of the remoteness of the islands, the peopling process of the Azores was slow, lasting over two centuries (Mendonc ßa, 1996). Settlers arrived mostly from mainland Portugal and the neighbouring Madeiran archipelago, but there were also minor contributions from elsewhere in Europe (Flanders, Spain, Italy, France, England, Germany and Scotland) (Matos, 1989), which is corroborated by human genetic data (Santos et al., 2003(Santos et al., , 2006Montiel et al., 2005). Also, from the late 15th century onwards, due to its location in the middle of the Atlantic, the Azores started to play an essential role as a stop-over. ...
... 240 km) and mainland is much larger than that of Bioko. It is therefore expected that human movement between Bioko and the coast of Cameroon has been much more frequent since the island was first colonized by the Bubi ethnical group, at the end of the last glaciation [64]. Finally, although the existence of ITS1 hybrid forms was initially suggested in G. p. palpalis of Equatorial Guinea [11], this hypothesis was later rejected by the same authors using microsatellite markers [10]. ...
... The high genetic diversity of Tenerife and Lanzarote is attributed to the location of these islands in the routes of maritime expansion from Portugal, a circumstance similar to that of Flores (Azores) as observed by Smith et al. (1992) and Santos et al. (2005). A different situation was described for Tristan da Cunha, where the small number of surnames counted (1816-1908) is explained by its isolation (Roberts 1971, Thomas & Thompson 1984. ...
... Thus, children who embark on their life-path from a less advantageous intergenerational ''platform'' seem to be particularly vulnerable to circulatory disease and death over the life-course. Despite the fact that female-headed households have proved to be a powerful indicator of childhood deprivation throughout history (Horrell, Humphries, & Voth, 2001), only a handful of studies have investigated the long-term health consequences of such childhood social conditions (Abade & Bertranpetit, 1995;Lund, Christensen, Holstein, Due, & Osler, 2006;Modin, 2003;Preston, Hill, & Drevenstedt, 1998). These studies all demonstrate an increased risk of adult mortality among individuals who were born outside marriage in the nineteenth or early twentieth century. ...
... PSQI [32] is a self-rated questionnaire that evaluates sleep quality over a 1-month time interval; PSQI has already been applied to MJD patients with the aim of increasing knowledge on the impact of sleep disturbances on disease manifestations (e.g., [33]). Depressive symptoms have also been reported in MJD patients; indeed, the presence of moderate-to-severe depressive scores in nearly 34% of MJD patients has been described [34]. Depression scores have been shown to correlate with motor impairment in MJD patients, but whether depression is more reactive and not primarily related to the disease process is a matter of debate (e.g., [35]), reinforcing the need for studies with a larger number of patients. ...