Background Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National... more Background Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARS-CoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementatio...
Background Early diagnosis and treatment are improving significantly the quality of life of patie... more Background Early diagnosis and treatment are improving significantly the quality of life of patients with cystic fibrosis (CF). This recessive disease is caused by a great variability of mutations in the CF transmembrane conductance (CFTR) gene, whose spectrum and frequency can be different across populations. Methods We performed a retrospective cross-sectional study of CF patients from the island of São Miguel (Azores, Portugal) through a clinical, genealogical, genetic and epidemiological investigation. The clinical course of patients was analyzed as a whole and according to their genotype. Results We identified 14 CF patients within a 23-year period, corresponding to a cumulative incidence of 1:3012 births, being three of them born from consanguineous unions. Genetic analysis revealed three CFTR genotypes: p.[Ser4Ter];[Gln1100Pro] was present in one patient with a less severe phenotype (1/14); c.[120del23];p.[Phe508del], a very rare one (2/14); and p.[Phe508del];[Phe508del] in t...
To study the genetic diversity of São Miguel's population we compared 21 microsatellite loci in 2... more To study the genetic diversity of São Miguel's population we compared 21 microsatellite loci in 204 individuals from São Miguel island and 103 individuals from mainland Portugal. The results show that São Miguel and mainland Portugal populations have an average gene diversity of 0.767 and 0.765, respectively. TPOX and D17S976 markers have the lowest ($0.6) and highest ($0.9) values, respectively, of gene diversity for both populations. Allele frequencies of all markers are comparable to other European populations. This result is corroborated by the genetic relationship analysis based on the NJ tree and principal component, where São Miguel, and probably, Azores is closely related to mainland Portugal. The comparison of F IS values for the mainland (0.0326) and the São Miguel (0.0111) samples suggests higher inbreeding in the mainland. Overall, the data suggests that São Miguel population does not show population structure and is behaving as an outbred population with high genetic diversity. Taken together, the data complements the settlement history of the São Miguel island and of the Azorean population, and will be crucial to predict and explain genotypes implicated in genetic diseases in the Azorean population.
The design of genetic studies of complex diseases is dependent on the extension and distribution ... more The design of genetic studies of complex diseases is dependent on the extension and distribution of linkage disequilibrium (LD) across the genome and populations. Here, we characterize the LD extension in the Azores (Western, Central and Eastern islands groups) and mainland Portugal populations. LD was evaluated in three chromosomic regions: the Xq13.3, the Y-chromosome and the HLA (6p21) for the Azorean population. The results obtained in the Western group for the Xq13.3 markers provide significant evidence of LD in 10 comparisons, after correction. In the São Miguel island population, the assessment of LD for HLA demonstrated a total of 13 out of 36 pairs with significant LD, with the largest genetic distance (2.5 Mb) between HLA-DRB1 and D6S265. The pairwise association between Y-markers in the Azorean population revealed 46% pairs with significant LD. In addition, D 0 analysis indicates that the Western group presents higher values when compared with the Central and Eastern groups. Taken together, the data show that the Azorean population presents a lower D 0 (0.142) compared with mainland Portugal (0.226). Although, both populations do not show extensive LD, the easy reconstruction of large pedigrees in the Azorean population is a valuable resource for the fine mapping of disease genes.
Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been ob... more Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been observed that only a proportion of individuals exposed to pathogenic species of Leptospira become infected and develop clinically evident disease. Moreover, little information is available in subsequent reinfections. In the present study, we determine if a first infection with leptospirosis protects against subsequent reinfection, and investigate which of the host genetic factors are involved in the susceptibility and resistance to leptospirosis. We conducted, in 2011, a retrospective hospital-based case-control study in the São Miguel Island population (Azores archipelago). In order to determine the seropositivity against pathogenic Leptospira after the first episode of leptospirosis, we performed a serological evaluation in 97 unrelated participants diagnosed with leptospirosis between 1992 and 2011. The results revealed that 46.4% of the 97 participants have circulating anti-Leptospira ...
The knowledge of population history, demography and genetic structure has proven to be fundamenta... more The knowledge of population history, demography and genetic structure has proven to be fundamental to address research in human genetics. Here, we describe the genetic diversity of the Azorean population and its affinity with other populations by the analysis of 13 microsatellite loci (TPOX,
The peopling of São Miguel Island in the 15th century was made by Portuguese and settlers of fore... more The peopling of São Miguel Island in the 15th century was made by Portuguese and settlers of foreign origin (Flemish, Jews, Moorish prisoners and black slaves), generating an admixture signature. Thus, to unravel São Miguel's population genetic background and to characterize its population's polymorphisms, we decided to establish a human DNA bank. Here, we describe the construction of the DNA bank and analyse the information of 997 samples obtained from healthy blood donors. The bank follows the international ethical guidelines, which include informed consent, confidentiality, anonymity of personal data, and abandonment in case of expressed will. DNA was isolated from blood samples, coded and immediately stored in a locked refrigerator. The identifiable DNA bank has self-reported data concerning sex, age, birth, current place of living, and parental birthplaces. The samples are representative of all the island's municipalities (r = 0.995, p b 0.01). The majority (87%) of the participants is male, with mean age of 36.3 years (18-64 years). Birthplace analysis reveals that 902 (90%) have both parents born in São Miguel. Moreover, 477 (54%) have their parents born in the same locality, confirming a relatively high rate of consanguinity in rural area. To date, this DNA bank was used to assess the Y-chromosome phylogeny and diversity in Azorean population. Now, we are analysing autosomal STRs for the better understanding of the gene pool and genetic structure of the archipelago's people.
Studies on linkage disequilibrium (LD) across the genome and populations have been used in recent... more Studies on linkage disequilibrium (LD) across the genome and populations have been used in recent years with the main objective of improving gene mapping of complex traits. Here, we characterize the patterns of genetic diversity of HLA loci and evaluate LD (D') extent in three genomic regions: Xq13.3, NRY and HLA. In addition, we examine the distribution of DXS1225-DXS8082 haplotype diversity in Azoreans and mainland Portuguese. Allele distribution has demonstrated that the São Miguel population is genetically very diverse; haplotype analysis revealed 100% discriminatory power for X-and Y-markers and 94.3% for HLA markers. Standardized multiallelic D' in these three genomic regions shows values lower than 0.33, thereby suggesting there is no extensive LD in the São Miguel population. Data regarding the distribution of DXS1225-DXS8082 haplotypes indicate that there are no significant differences among all the populations studied, (Azorean geographical groups, the Azores archipelago and mainland Portugal). Moreover, in these as well as in other European populations, the most frequent DXS1225-DXS8082 haplotype is 210-219. Even though São Miguel islanders and Azoreans do not constitute isolated populations and show LD for only very short physical distances, certain characteristics, such as the absence of genetic structure, the same environment and the possibility of constructing extensive pedigrees through church and civil records, offer an opportunity for dissecting the genetic background of complex diseases in these populations.
Allele frequencies for 15 short tandem repeats (STR) loci were obtained from a sample of 2038 ind... more Allele frequencies for 15 short tandem repeats (STR) loci were obtained from a sample of 2038 individuals undergoing paternity testing. The population is from Rio Grande do Sul, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the AmpFlSTR 1 Identifiler (Applied Biosystems) commercial kit. The most polymorphic locus was D2S1338. Mutation rates were ascertained from this population sample. All the loci analysed reached the Hardy-Weinberg equilibrium. The results of genetic distance are consistent with the European-derived origins of Rio Grande do Sul population.
Knowledge of population ancestry from genetic markers is essential, for example, to understand th... more Knowledge of population ancestry from genetic markers is essential, for example, to understand the history of human migration and to carry out admixture and association studies. Here we assess the genome ancestry of the Azorean population through analysis of six Alu polymorphic sites (TPA-25, ACE, APO, B65, PV92, and D1) in 65 Azoreans and 30 Portuguese unrelated blood donors and compare data for the Y-chromosome and mtDNA. Allele frequencies were calculated by direct counting. Statistical analysis was performed using Arlequin 2.0. Nei's genetic distance was calculated with DISPAN software, and trees were constructed by neighbor joining (NJ) using PHYLIP 3.63. The results show that all Alu insertions were polymorphic. APO is the closest to fixation. The less frequent insertions are PV92 and D1 in the Azores and Portugal, respectively. ACE and TPA-25 show the highest values of heterozygosity in both populations. Allele frequencies are very similar to those obtained in European populations. These results are validated by the Y-chromosome and mtDNA data, where the majority of the maternal and paternal lineages are European. Overall, these data are reflected in the phylogenetic tree, in which the Azoreans and the Portuguese branch with Catalans, Andalusians, Moroccans, and Algerians. We conclude that the population of the Azores shows no significant genetic differences from that of mainland Portugal and that it is an outbred population. Moreover, the data validate the use of Alu insertion polymorphisms to assess the origin and history of human populations. Am.
Summary Background The Azorean population presents the highest standardized mortality rate for ca... more Summary Background The Azorean population presents the highest standardized mortality rate for cardiovascular diseases (CVD) when compared to mainland Portugal and other populations. Since thrombosis is a common cause of CVD, we assessed four polymorphisms in three thrombotic risk genes – F5 (G1691A), F2 (G20210A) and MTHFR (C677T, A1298C), in 469 healthy blood donors from São Miguel Island (Azores). We also analysed the CYP2C9 (C430T, A1075C) and VKORC1 (G1639A) variants in fifty-eight individuals with predisposition to thrombosis (possessing at least one variation in F5 or F2 genes and one in MTHFR) to evaluate their warfarin drug response genetic profiles. Results Among the 469 individuals, the data showed that thrombotic risk allele frequencies – 1691A (4.9%), 20210A (1.8%), 677T (41.7%) and 1298C (24.8%) – were similar to other Caucasians, but significantly different from mainland Portuguese (χ2, p < 0.001). The combined analysis of these variants identified twenty-two diffe...
Currently, direct detection of Leptospira can be done in clinical laboratories by conventional an... more Currently, direct detection of Leptospira can be done in clinical laboratories by conventional and by real-time PCR (qRT-PCR). We tested a biobank of paired samples of serum and urine from the same patient (202 patients) presenting at the hospital in an area endemic for leptospirosis using qRT-PCR followed by high resolution melting (HRM) analysis. The results were compared with those obtained by conventional nested PCR and with the serologic gold standard microscopic agglutination test (MAT). Differences were resolved by sequencing. qRT-PCR-HRM was positive for 46 of the 202 patients (22.7%, accuracy 100%) which is consistent with known prevalence of leptospirosis in the Azores. MAT results were positive for 3 of the 46 patients (6.5%). Analysis of paired samples allowed us to identify the illness point at which patients presented at the hospital: onset, dissemination or excretion. The melting curve analysis of Leptospira species revealed that 60.9% (28/46) of patients were infecte...
Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal rece... more Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal recessive disease, characterized mainly by skin blistering at birth or shortly thereafter, progressive muscle weakness, and rarely by alopecia. EBS-MD is caused by mutations in the PLEC gene (OMIM *601282), which encodes plectin, a structural protein expressed in several tissues, including epithelia and muscle. We describe a patient affected with EBS-MD and diffuse alopecia in which we identified a novel pathogenic mutation by PCR amplification of all coding exons and exon-intron boundaries of PLEC gene, followed by bidirectional Sanger sequencing. The patient, a 28-year-old female and only child of consanguineous healthy parents, was born after uneventful pregnancy. At 2 days of age, she developed skin and oral mucosal blistering, accompanied by voice hoarseness. On physical examination as an adult, we observed diffuse non-scarring alopecia on the scalp, onychodystrophy (pachyonychia) in al...
Background: Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an au... more Background: Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal recessive disease, characterized mainly by skin blistering at birth or shortly thereafter, progressive muscle weakness, and rarely by alopecia. EBS-MD is caused by mutations in the PLEC gene (OMIM *601282), which encodes plectin, a structural protein expressed in several tissues, including epithelia and muscle. We describe a patient affected with EBS-MD and diffuse alopecia in which we identified a novel pathogenic mutation by PCR amplification of all coding exons and exon–intron boundaries of PLEC gene, followed by bidirectional Sanger sequencing. Case presentation: The patient, a 28-year-old female and only child of consanguineous healthy parents, was born after uneventful pregnancy. At 2 days of age, she developed skin and oral mucosal blistering, accompanied by voice hoarseness. On physical examination as an adult, we observed diffuse non-scarring alopecia on the scalp, onych...
Mortality and morbidity due to cardiovascular diseases (CVD) place Azores with the highest value ... more Mortality and morbidity due to cardiovascular diseases (CVD) place Azores with the highest value when compared with other Portuguese populations. The present study aimed to investigate the genetic determinants of CVD by the analysis of 19 SNPs in three genomic regions: USF1, 9p21 and LDLR. Genotype evaluation of rs1333049 (9p21 region) showed that 19.4% of individuals present homozygosity for the risk allele (RA). The combined USF1/9p21/LDLR analysis demonstrated that 2.9% of individuals are homozygous genotypes for 10 RA, suggesting that Azoreans have a considerable genetic risk for CVD. Joint USF1/LDLR study evidenced gender differences for lipids metabolism and CVD risk. In conclusion, in small island populations, homozygosity must be taken in consideration when performing risk profile studies. These results constitute a valuable resource for determining population's attributable risk and for CVD case-control studies currently in development in Azores.
Background Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National... more Background Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARS-CoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementatio...
Background Early diagnosis and treatment are improving significantly the quality of life of patie... more Background Early diagnosis and treatment are improving significantly the quality of life of patients with cystic fibrosis (CF). This recessive disease is caused by a great variability of mutations in the CF transmembrane conductance (CFTR) gene, whose spectrum and frequency can be different across populations. Methods We performed a retrospective cross-sectional study of CF patients from the island of São Miguel (Azores, Portugal) through a clinical, genealogical, genetic and epidemiological investigation. The clinical course of patients was analyzed as a whole and according to their genotype. Results We identified 14 CF patients within a 23-year period, corresponding to a cumulative incidence of 1:3012 births, being three of them born from consanguineous unions. Genetic analysis revealed three CFTR genotypes: p.[Ser4Ter];[Gln1100Pro] was present in one patient with a less severe phenotype (1/14); c.[120del23];p.[Phe508del], a very rare one (2/14); and p.[Phe508del];[Phe508del] in t...
To study the genetic diversity of São Miguel's population we compared 21 microsatellite loci in 2... more To study the genetic diversity of São Miguel's population we compared 21 microsatellite loci in 204 individuals from São Miguel island and 103 individuals from mainland Portugal. The results show that São Miguel and mainland Portugal populations have an average gene diversity of 0.767 and 0.765, respectively. TPOX and D17S976 markers have the lowest ($0.6) and highest ($0.9) values, respectively, of gene diversity for both populations. Allele frequencies of all markers are comparable to other European populations. This result is corroborated by the genetic relationship analysis based on the NJ tree and principal component, where São Miguel, and probably, Azores is closely related to mainland Portugal. The comparison of F IS values for the mainland (0.0326) and the São Miguel (0.0111) samples suggests higher inbreeding in the mainland. Overall, the data suggests that São Miguel population does not show population structure and is behaving as an outbred population with high genetic diversity. Taken together, the data complements the settlement history of the São Miguel island and of the Azorean population, and will be crucial to predict and explain genotypes implicated in genetic diseases in the Azorean population.
The design of genetic studies of complex diseases is dependent on the extension and distribution ... more The design of genetic studies of complex diseases is dependent on the extension and distribution of linkage disequilibrium (LD) across the genome and populations. Here, we characterize the LD extension in the Azores (Western, Central and Eastern islands groups) and mainland Portugal populations. LD was evaluated in three chromosomic regions: the Xq13.3, the Y-chromosome and the HLA (6p21) for the Azorean population. The results obtained in the Western group for the Xq13.3 markers provide significant evidence of LD in 10 comparisons, after correction. In the São Miguel island population, the assessment of LD for HLA demonstrated a total of 13 out of 36 pairs with significant LD, with the largest genetic distance (2.5 Mb) between HLA-DRB1 and D6S265. The pairwise association between Y-markers in the Azorean population revealed 46% pairs with significant LD. In addition, D 0 analysis indicates that the Western group presents higher values when compared with the Central and Eastern groups. Taken together, the data show that the Azorean population presents a lower D 0 (0.142) compared with mainland Portugal (0.226). Although, both populations do not show extensive LD, the easy reconstruction of large pedigrees in the Azorean population is a valuable resource for the fine mapping of disease genes.
Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been ob... more Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been observed that only a proportion of individuals exposed to pathogenic species of Leptospira become infected and develop clinically evident disease. Moreover, little information is available in subsequent reinfections. In the present study, we determine if a first infection with leptospirosis protects against subsequent reinfection, and investigate which of the host genetic factors are involved in the susceptibility and resistance to leptospirosis. We conducted, in 2011, a retrospective hospital-based case-control study in the São Miguel Island population (Azores archipelago). In order to determine the seropositivity against pathogenic Leptospira after the first episode of leptospirosis, we performed a serological evaluation in 97 unrelated participants diagnosed with leptospirosis between 1992 and 2011. The results revealed that 46.4% of the 97 participants have circulating anti-Leptospira ...
The knowledge of population history, demography and genetic structure has proven to be fundamenta... more The knowledge of population history, demography and genetic structure has proven to be fundamental to address research in human genetics. Here, we describe the genetic diversity of the Azorean population and its affinity with other populations by the analysis of 13 microsatellite loci (TPOX,
The peopling of São Miguel Island in the 15th century was made by Portuguese and settlers of fore... more The peopling of São Miguel Island in the 15th century was made by Portuguese and settlers of foreign origin (Flemish, Jews, Moorish prisoners and black slaves), generating an admixture signature. Thus, to unravel São Miguel's population genetic background and to characterize its population's polymorphisms, we decided to establish a human DNA bank. Here, we describe the construction of the DNA bank and analyse the information of 997 samples obtained from healthy blood donors. The bank follows the international ethical guidelines, which include informed consent, confidentiality, anonymity of personal data, and abandonment in case of expressed will. DNA was isolated from blood samples, coded and immediately stored in a locked refrigerator. The identifiable DNA bank has self-reported data concerning sex, age, birth, current place of living, and parental birthplaces. The samples are representative of all the island's municipalities (r = 0.995, p b 0.01). The majority (87%) of the participants is male, with mean age of 36.3 years (18-64 years). Birthplace analysis reveals that 902 (90%) have both parents born in São Miguel. Moreover, 477 (54%) have their parents born in the same locality, confirming a relatively high rate of consanguinity in rural area. To date, this DNA bank was used to assess the Y-chromosome phylogeny and diversity in Azorean population. Now, we are analysing autosomal STRs for the better understanding of the gene pool and genetic structure of the archipelago's people.
Studies on linkage disequilibrium (LD) across the genome and populations have been used in recent... more Studies on linkage disequilibrium (LD) across the genome and populations have been used in recent years with the main objective of improving gene mapping of complex traits. Here, we characterize the patterns of genetic diversity of HLA loci and evaluate LD (D') extent in three genomic regions: Xq13.3, NRY and HLA. In addition, we examine the distribution of DXS1225-DXS8082 haplotype diversity in Azoreans and mainland Portuguese. Allele distribution has demonstrated that the São Miguel population is genetically very diverse; haplotype analysis revealed 100% discriminatory power for X-and Y-markers and 94.3% for HLA markers. Standardized multiallelic D' in these three genomic regions shows values lower than 0.33, thereby suggesting there is no extensive LD in the São Miguel population. Data regarding the distribution of DXS1225-DXS8082 haplotypes indicate that there are no significant differences among all the populations studied, (Azorean geographical groups, the Azores archipelago and mainland Portugal). Moreover, in these as well as in other European populations, the most frequent DXS1225-DXS8082 haplotype is 210-219. Even though São Miguel islanders and Azoreans do not constitute isolated populations and show LD for only very short physical distances, certain characteristics, such as the absence of genetic structure, the same environment and the possibility of constructing extensive pedigrees through church and civil records, offer an opportunity for dissecting the genetic background of complex diseases in these populations.
Allele frequencies for 15 short tandem repeats (STR) loci were obtained from a sample of 2038 ind... more Allele frequencies for 15 short tandem repeats (STR) loci were obtained from a sample of 2038 individuals undergoing paternity testing. The population is from Rio Grande do Sul, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the AmpFlSTR 1 Identifiler (Applied Biosystems) commercial kit. The most polymorphic locus was D2S1338. Mutation rates were ascertained from this population sample. All the loci analysed reached the Hardy-Weinberg equilibrium. The results of genetic distance are consistent with the European-derived origins of Rio Grande do Sul population.
Knowledge of population ancestry from genetic markers is essential, for example, to understand th... more Knowledge of population ancestry from genetic markers is essential, for example, to understand the history of human migration and to carry out admixture and association studies. Here we assess the genome ancestry of the Azorean population through analysis of six Alu polymorphic sites (TPA-25, ACE, APO, B65, PV92, and D1) in 65 Azoreans and 30 Portuguese unrelated blood donors and compare data for the Y-chromosome and mtDNA. Allele frequencies were calculated by direct counting. Statistical analysis was performed using Arlequin 2.0. Nei's genetic distance was calculated with DISPAN software, and trees were constructed by neighbor joining (NJ) using PHYLIP 3.63. The results show that all Alu insertions were polymorphic. APO is the closest to fixation. The less frequent insertions are PV92 and D1 in the Azores and Portugal, respectively. ACE and TPA-25 show the highest values of heterozygosity in both populations. Allele frequencies are very similar to those obtained in European populations. These results are validated by the Y-chromosome and mtDNA data, where the majority of the maternal and paternal lineages are European. Overall, these data are reflected in the phylogenetic tree, in which the Azoreans and the Portuguese branch with Catalans, Andalusians, Moroccans, and Algerians. We conclude that the population of the Azores shows no significant genetic differences from that of mainland Portugal and that it is an outbred population. Moreover, the data validate the use of Alu insertion polymorphisms to assess the origin and history of human populations. Am.
Summary Background The Azorean population presents the highest standardized mortality rate for ca... more Summary Background The Azorean population presents the highest standardized mortality rate for cardiovascular diseases (CVD) when compared to mainland Portugal and other populations. Since thrombosis is a common cause of CVD, we assessed four polymorphisms in three thrombotic risk genes – F5 (G1691A), F2 (G20210A) and MTHFR (C677T, A1298C), in 469 healthy blood donors from São Miguel Island (Azores). We also analysed the CYP2C9 (C430T, A1075C) and VKORC1 (G1639A) variants in fifty-eight individuals with predisposition to thrombosis (possessing at least one variation in F5 or F2 genes and one in MTHFR) to evaluate their warfarin drug response genetic profiles. Results Among the 469 individuals, the data showed that thrombotic risk allele frequencies – 1691A (4.9%), 20210A (1.8%), 677T (41.7%) and 1298C (24.8%) – were similar to other Caucasians, but significantly different from mainland Portuguese (χ2, p < 0.001). The combined analysis of these variants identified twenty-two diffe...
Currently, direct detection of Leptospira can be done in clinical laboratories by conventional an... more Currently, direct detection of Leptospira can be done in clinical laboratories by conventional and by real-time PCR (qRT-PCR). We tested a biobank of paired samples of serum and urine from the same patient (202 patients) presenting at the hospital in an area endemic for leptospirosis using qRT-PCR followed by high resolution melting (HRM) analysis. The results were compared with those obtained by conventional nested PCR and with the serologic gold standard microscopic agglutination test (MAT). Differences were resolved by sequencing. qRT-PCR-HRM was positive for 46 of the 202 patients (22.7%, accuracy 100%) which is consistent with known prevalence of leptospirosis in the Azores. MAT results were positive for 3 of the 46 patients (6.5%). Analysis of paired samples allowed us to identify the illness point at which patients presented at the hospital: onset, dissemination or excretion. The melting curve analysis of Leptospira species revealed that 60.9% (28/46) of patients were infecte...
Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal rece... more Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal recessive disease, characterized mainly by skin blistering at birth or shortly thereafter, progressive muscle weakness, and rarely by alopecia. EBS-MD is caused by mutations in the PLEC gene (OMIM *601282), which encodes plectin, a structural protein expressed in several tissues, including epithelia and muscle. We describe a patient affected with EBS-MD and diffuse alopecia in which we identified a novel pathogenic mutation by PCR amplification of all coding exons and exon-intron boundaries of PLEC gene, followed by bidirectional Sanger sequencing. The patient, a 28-year-old female and only child of consanguineous healthy parents, was born after uneventful pregnancy. At 2 days of age, she developed skin and oral mucosal blistering, accompanied by voice hoarseness. On physical examination as an adult, we observed diffuse non-scarring alopecia on the scalp, onychodystrophy (pachyonychia) in al...
Background: Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an au... more Background: Epidermolysis bullosa simplex with muscular dystrophy (EBS-MD; OMIM #226670) is an autosomal recessive disease, characterized mainly by skin blistering at birth or shortly thereafter, progressive muscle weakness, and rarely by alopecia. EBS-MD is caused by mutations in the PLEC gene (OMIM *601282), which encodes plectin, a structural protein expressed in several tissues, including epithelia and muscle. We describe a patient affected with EBS-MD and diffuse alopecia in which we identified a novel pathogenic mutation by PCR amplification of all coding exons and exon–intron boundaries of PLEC gene, followed by bidirectional Sanger sequencing. Case presentation: The patient, a 28-year-old female and only child of consanguineous healthy parents, was born after uneventful pregnancy. At 2 days of age, she developed skin and oral mucosal blistering, accompanied by voice hoarseness. On physical examination as an adult, we observed diffuse non-scarring alopecia on the scalp, onych...
Mortality and morbidity due to cardiovascular diseases (CVD) place Azores with the highest value ... more Mortality and morbidity due to cardiovascular diseases (CVD) place Azores with the highest value when compared with other Portuguese populations. The present study aimed to investigate the genetic determinants of CVD by the analysis of 19 SNPs in three genomic regions: USF1, 9p21 and LDLR. Genotype evaluation of rs1333049 (9p21 region) showed that 19.4% of individuals present homozygosity for the risk allele (RA). The combined USF1/9p21/LDLR analysis demonstrated that 2.9% of individuals are homozygous genotypes for 10 RA, suggesting that Azoreans have a considerable genetic risk for CVD. Joint USF1/LDLR study evidenced gender differences for lipids metabolism and CVD risk. In conclusion, in small island populations, homozygosity must be taken in consideration when performing risk profile studies. These results constitute a valuable resource for determining population's attributable risk and for CVD case-control studies currently in development in Azores.
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Papers by Claudia Branco