Background: Complex diseases such as coronary artery disease, hypertension or diabetes are usuall... more Background: Complex diseases such as coronary artery disease, hypertension or diabetes are usually caused by the individual susceptibility to multiple genes, environmental factors, and the interaction between them. The PON1 enzyme has been implicated in the pathogenesis of atherosclerosis and coronary artery disease (CAD). Two common polymorphisms in the coding region of the PON1 gene which lead to a Gln (Q)/Arg (R) substitution at position192 and Leu/Met substitution at position 55 influence PON1 activity. Aims: 1. To evaluate the PON1 polymorphisms association and CAD risk. 2. To study the interaction between PON1polymorphisms and others located in different candidate genes. Methods: We evaluated in 298 CAD patients and 298 healthy individuals the risk of CAD associated with PON1 192Q/R and 55 Leu/Met polymorphisms. Then, we evaluated the risk of the PON1 interaction with ECA DD; ECA 8 GG and MTHFR 1298 AA. Finally through a regression logistics model we evaluated which variables (genetic, biochemical and environmental) were linked, in a significant and independent way, with CAD. Results: We verified that PON1 55 MM genotype, had a higher distribution in the CAD population, but did not reach statistical significance as risk factor for CAD, and PON1 199 RR presented a relative risk 80% higher in relation to the population without that polymorphism. The association of mutated polymorphisms in the same gene belonging to the same pathophysiological systems that codify for the same enzymatic protein, (PON 55 MM + PON 192 RR), did not increase the risk for DAC (OR=1.767; p=0.057, Ns). The interaction between PON1 192 RR and MTHFR 1298 AA, sited in different genes, increased the risk for CAD. Similarly, the association between PON1 RR and ECA 8 GG, was linked to an even higher risk (OR=5.6; p=0.002). After logistic regression, smoking habits, family history, fibrinogen, diabetes, Lp (a) and PON1 192 RR + ECA 8 GG interaction, were kept in the regression model and proved to be an independent risk factors for CAD. Conclusion: If separately estimated, PON1 192 RR genotype presented a relative risk for CAD 80% higher than in the population without this genotype. The association with other genetic polymorphisms sited in different genes, codifying for different enzymes and belonging to different pathophysiological systems, always increased the risk for CAD. After correction for the other classical and biochemical risk factors, PON1 192 RR + ECA 8 GG association remained a significant and independent risk factor for CAD.
Conventional coronary artery disease (CAD) risk factors like age, gender, blood lipids, hypertens... more Conventional coronary artery disease (CAD) risk factors like age, gender, blood lipids, hypertension and smoking have been the basis of CAD risk prediction algorithms, but provide only modest discrimination. Genetic risk score (GRS) may provide improved discrimination over and above conventional risk factors. Here we analyzed the genetic risk of CAD in subjects from Pakistan, using a GRS of 21 variants in 18 genes and examined whether the GRS is associated with blood lipid levels. 625 (405 cases and 220 controls) subjects were genotyped for variants, NOS3 rs1799983, SMAD3 rs17228212, APOB rs1042031, LPA rs3798220, LPA rs10455872, SORT1 rs646776, APOE rs429358, GLUL rs10911021, FTO rs9939609, MIA3 rs17465637, CDKN2Ars10757274, DAB2IP rs7025486, CXCL12 rs1746048, ACE rs4341, APOA5 rs662799, CETP rs708272, MRAS rs9818870, LPL rs328, LPL rs1801177, PCSK9 rs11591147 and APOE rs7412 by TaqMan and KASPar allele discrimination techniques. Individually, the single SNPs were not associated wi...
Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Seve... more Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Several metabolites have been related to its quality and safety, such as 5-hydroxymethylfurfural (HMF), furfural, sotolon, and ethyl carbamate (EC). These compounds were quantified over a three-year period to assess their formation rate according to the ageing procedure used: canteiro vs. estufagem. Estufagem, which includes thermal processing of young MWs, promoted greater HMF, furfural, and sotolon accumulation, especially in sweet wines, in which sotolon contributed significantly to aroma (odour active values up to 17.5). Tinta Negra revealed a higher predisposition to form EC while Malvasia and Sercial were less prone to its formation. The formation of furfural, HMF, and EC strongly correlated with the ageing time. Sotolon had a strong correlation with the ageing time in canteiro (r = 0.79) and a moderate correlation in estufagem (r = 0.65). In both ageing procedures, sotolon, furfural, ...
Madeira wine (MW) oxidative aging results in the formation of several key aromas. Little is still... more Madeira wine (MW) oxidative aging results in the formation of several key aromas. Little is still known about their odor relevance to the aroma of the most commercialized MWs. This report presents an in-depth study of the odor impact of sotolon in MW blends. First, its odor perception was estimated in MWs according to ASTM E679, testing different 3-year-old (3-yo) commercial blends. The odor relevance of sotolon in the aroma of 3-, 5-, and 10-yo commercial blends (89 MWs) was then appraised by calculating its Odor Activity Value (OAV), after determining its content by RP-HPLC-MS/MS. The sotolon odor perception in MW was as low as 23 µg/L, although it was found that little differences in the wine matrix influenced its perception. OAVs varied between 0.1 and 22, increasing with the blend age. Considering that 16% of the OAVs are higher than 10 (mostly ≥ 10-yo), sotolon was found to be a key contributor to the overall aroma MW blends.
Introduction: Arterial hypertension is a complex, multifactorial disease, controlled by genetic a... more Introduction: Arterial hypertension is a complex, multifactorial disease, controlled by genetic and environmental factors.Objective: Evaluate the genetic susceptibility for developing arterial hypertension and its association with the traditional risk factors in the outbreak of this pathology.Material and Methods: Case-control study with 1712 individuals, mean age of 51.0 ± 7.9 years (860 hypertensive patients and 852 controls). Biochemical and traditional risk factors, and genetic variants were evaluated: ACE I/D rs4340, ACE A2350G rs4343, AGT T174M rs4762, AGT M235T rs699 AGTR1 A1166C rs5186, CYP11B2 -344 C/T rs1799998, ADRB1 R389G rs1801253, ADRB2 R16G rs1042713, ADD1 G460W rs4961, SCNN1G G173A rs5718, GNB3 C825T rs5443, ATP2B1 A/G rs2681472, CYP17A1 T/C rs11191548, SLC4A2 C/T rs2303934. The risk of each gene for hypertension was estimated by the dominant, recessive, co-dominant and multiplicative models. By logistic regression, variables associated with hypertension were evaluat...
Genetic testing and molecular biomarkers, Jan 5, 2017
Essential hypertension (EH) is a disease in which both environment and genes have an important ro... more Essential hypertension (EH) is a disease in which both environment and genes have an important role. This study was designed to identify the interaction model between genetic variants and environmental risk factors that most highly potentiates EH development. We performed a case-control study with 1641 participants (mean age 50.6 ± 8.1 years), specifically 848 patients with EH and 793 controls, adjusted for gender and age. Traditional risk factors, biochemical and genetic parameters, including the genotypic discrimination of 14 genetic variants previously associated with EH, were investigated. Multifactorial dimensionality reduction (MDR) software was used to analyze gene-environment interactions. Validation was performed using logistic regression analysis with environmental risk factors, significant genetic variants, and the best MDR model. The best model indicates that the interactions among the ADD1 rs4961 640T allele, diabetes, and obesity (body mass index ≥30) increase approxim...
Elevated levels of plasma homocysteine, an independent risk factor and a strong predictor of mort... more Elevated levels of plasma homocysteine, an independent risk factor and a strong predictor of mortality in patients with coronary artery disease (CAD), can result from nutritional deficiencies or genetic errors, including methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms. The contribution of these polymorphisms in the development of CAD remains controversial. We analysed the impact of MTHFR C677T and A1298C on fasting homocysteine and CAD in 298 CAD patients proved by angiography and 510 control subjects from the Island of Madeira (Portugal). After adjustment for other risk factors, plasma homocysteine remained independently correlated with CAD. Serum homocysteine was significantly higher in individuals with 677TT and 1298AA genotypes. There was no difference in the distribution of MTHFR677 genotypes between cases and controls but a significant increase in 1298AA prevalence was found in CAD patients. In spite of the clear effect of C677T mutation on elevated homocysteine levels we only found an association between 1298AA genotype and CAD in this population. The simultaneous presence of 677CT and 1298AA genotypes provides a significant risk of developing the disease, while the 1298AC genotype, combined with 677CC, shows a significant trend towards a decrease in CAD occurrence. The data shows an independent association between
Background Several polymorphisms within the renin-angiotensin system cluster of genes have been a... more Background Several polymorphisms within the renin-angiotensin system cluster of genes have been associated with the advent of coronary artery disease (CAD) or related pathologies. We investigated the distribution of 5 of these polymorphisms in order to find any association with CAD development and distinguish if any of the biochemical and behavioural factors interact with genetic polymorphisms in the advent of the disease. Methods ACE I/D (rs4340), ACE A11860G (rs4343), AT1R A1166C (rs5186), AGT T174M (rs4762) and AGT M235T (rs699) gene polymorphisms were PCR-RFLP analysed in 298 CAD patients and 510 controls from Portugal. Several biochemical and behavioural markers were obtained. Results ACE I/D DD and ACE11860 GG genotypes are risk factors for CAD in this population. The simultaneous presence of ACE I/D I and ACE11860 A alleles corresponds to a significant trend towards a decrease in CAD incidence. We found several synergistic effects between the studied polymorphisms and classic...
Eight microsatellite loci previously reported were assessed for their utility in parentage assign... more Eight microsatellite loci previously reported were assessed for their utility in parentage assignment in 96 individuals belonging to natural populations of the blackspot seabream Pagellus bogaraveo (Brˇnnick, 1768) from the Mediterranean and Northeast Atlantic regions. At the mtDNA level, no di¡erentiation was found between these two regions but based on microsatellite data an overall discrete genetic di¡erentiation is perceivable between the two regions separated by the Strait of Gibraltar. The number of alleles per locus ranged from 8 to 30. A database constructed with allele frequency data from six populations was used in a simulation parentage assignment test using the software CERVUS. The test showed that the number of markers used is enough to perform parentage assignments with real data. The polymorphic information content for each locus was very high (mean value of 0.849), with a total exclusionary power of 0.9995. In summary, seven of the eight microsatellites analysed proved to be su⁄cient and powerful tools for parentage assignment in hatcheries and the allele frequency data given here can be used to perform pedigree analysis against which real data may be tested.
Revista portuguesa de cardiologia : orgao oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, Jun 28, 2018
Hypertension is an important public health problem, affecting about 25% of the adult population w... more Hypertension is an important public health problem, affecting about 25% of the adult population worldwide.1 Genetic and environmental factors contribute to its pathogenesis. The T allele of the C825T polymorphism of the beta 3 subunit of G protein (rs5443) leads to the production of a truncated variant that enhances intracellular signaling and may interfere with the regulation of blood pressure. This genetic variant has been described as a risk factor for hypertension, although study results are controversial. The objective of this study was to analyze the association of the C825T polymorphism of the GNB3 gene with the occurrence of hypertension in a Portuguese population from the Madeira archipelago. A case-control study was performed with 1641 Caucasian individuals (mean age 50.6±8.1 years), 848 with hypertension and 793 controls. Blood was collected from all participants for biochemical and genetic analysis, including genotyping of the C825T polymorphism. Logistic regression anal...
After publication, the authors were alerted to ambiguous results in assaying marker 12f2. The lac... more After publication, the authors were alerted to ambiguous results in assaying marker 12f2. The lack of a distinct band defines haplogroup J lineages that can be a false-negative case when DNA is of poor quality and when using different DNA or primer concentrations. All J-chromosomes were typed using a phylogenetically equivalent binary SNP marker M304, described in:
A total of 553 Y-chromosomes were analyzed from mainland Portugal and the North Atlantic Archipel... more A total of 553 Y-chromosomes were analyzed from mainland Portugal and the North Atlantic Archipelagos of Açores and Madeira, in order to characterize the genetic composition of their male gene pool. A large majority (78-83% of each population) of the male lineages could be classified as belonging to three basic Y chromosomal haplogroups, R1b, J, and E3b. While R1b, accounting for more than half of the lineages in any of the Portuguese subpopulations, is a characteristic marker of many different West European populations, haplogroups J and E3b consist of lineages that are typical of the circum-Mediterranean region or even East Africa. The highly diverse haplogroup E3b in Portuguese likely combines sub-clades of distinct origins. The present composition of the Y chromosomes in Portugal in this haplogroup likely reflects a pre-Arab component shared with North African populations or testifies, at least in part, to the influence of Sephardic Jews. In contrast to the marginally low sub-Saharan African Y chromosome component in Portuguese, such lineages have been detected at a moderately high frequency in our previous survey of mtDNA from the same samples, indicating the presence of sex-related gene flow, most likely mediated by the Atlantic slave trade.
Background: Complex diseases such as coronary artery disease, hypertension or diabetes are usuall... more Background: Complex diseases such as coronary artery disease, hypertension or diabetes are usually caused by the individual susceptibility to multiple genes, environmental factors, and the interaction between them. The PON1 enzyme has been implicated in the pathogenesis of atherosclerosis and coronary artery disease (CAD). Two common polymorphisms in the coding region of the PON1 gene which lead to a Gln (Q)/Arg (R) substitution at position192 and Leu/Met substitution at position 55 influence PON1 activity. Aims: 1. To evaluate the PON1 polymorphisms association and CAD risk. 2. To study the interaction between PON1polymorphisms and others located in different candidate genes. Methods: We evaluated in 298 CAD patients and 298 healthy individuals the risk of CAD associated with PON1 192Q/R and 55 Leu/Met polymorphisms. Then, we evaluated the risk of the PON1 interaction with ECA DD; ECA 8 GG and MTHFR 1298 AA. Finally through a regression logistics model we evaluated which variables (genetic, biochemical and environmental) were linked, in a significant and independent way, with CAD. Results: We verified that PON1 55 MM genotype, had a higher distribution in the CAD population, but did not reach statistical significance as risk factor for CAD, and PON1 199 RR presented a relative risk 80% higher in relation to the population without that polymorphism. The association of mutated polymorphisms in the same gene belonging to the same pathophysiological systems that codify for the same enzymatic protein, (PON 55 MM + PON 192 RR), did not increase the risk for DAC (OR=1.767; p=0.057, Ns). The interaction between PON1 192 RR and MTHFR 1298 AA, sited in different genes, increased the risk for CAD. Similarly, the association between PON1 RR and ECA 8 GG, was linked to an even higher risk (OR=5.6; p=0.002). After logistic regression, smoking habits, family history, fibrinogen, diabetes, Lp (a) and PON1 192 RR + ECA 8 GG interaction, were kept in the regression model and proved to be an independent risk factors for CAD. Conclusion: If separately estimated, PON1 192 RR genotype presented a relative risk for CAD 80% higher than in the population without this genotype. The association with other genetic polymorphisms sited in different genes, codifying for different enzymes and belonging to different pathophysiological systems, always increased the risk for CAD. After correction for the other classical and biochemical risk factors, PON1 192 RR + ECA 8 GG association remained a significant and independent risk factor for CAD.
Conventional coronary artery disease (CAD) risk factors like age, gender, blood lipids, hypertens... more Conventional coronary artery disease (CAD) risk factors like age, gender, blood lipids, hypertension and smoking have been the basis of CAD risk prediction algorithms, but provide only modest discrimination. Genetic risk score (GRS) may provide improved discrimination over and above conventional risk factors. Here we analyzed the genetic risk of CAD in subjects from Pakistan, using a GRS of 21 variants in 18 genes and examined whether the GRS is associated with blood lipid levels. 625 (405 cases and 220 controls) subjects were genotyped for variants, NOS3 rs1799983, SMAD3 rs17228212, APOB rs1042031, LPA rs3798220, LPA rs10455872, SORT1 rs646776, APOE rs429358, GLUL rs10911021, FTO rs9939609, MIA3 rs17465637, CDKN2Ars10757274, DAB2IP rs7025486, CXCL12 rs1746048, ACE rs4341, APOA5 rs662799, CETP rs708272, MRAS rs9818870, LPL rs328, LPL rs1801177, PCSK9 rs11591147 and APOE rs7412 by TaqMan and KASPar allele discrimination techniques. Individually, the single SNPs were not associated wi...
Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Seve... more Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Several metabolites have been related to its quality and safety, such as 5-hydroxymethylfurfural (HMF), furfural, sotolon, and ethyl carbamate (EC). These compounds were quantified over a three-year period to assess their formation rate according to the ageing procedure used: canteiro vs. estufagem. Estufagem, which includes thermal processing of young MWs, promoted greater HMF, furfural, and sotolon accumulation, especially in sweet wines, in which sotolon contributed significantly to aroma (odour active values up to 17.5). Tinta Negra revealed a higher predisposition to form EC while Malvasia and Sercial were less prone to its formation. The formation of furfural, HMF, and EC strongly correlated with the ageing time. Sotolon had a strong correlation with the ageing time in canteiro (r = 0.79) and a moderate correlation in estufagem (r = 0.65). In both ageing procedures, sotolon, furfural, ...
Madeira wine (MW) oxidative aging results in the formation of several key aromas. Little is still... more Madeira wine (MW) oxidative aging results in the formation of several key aromas. Little is still known about their odor relevance to the aroma of the most commercialized MWs. This report presents an in-depth study of the odor impact of sotolon in MW blends. First, its odor perception was estimated in MWs according to ASTM E679, testing different 3-year-old (3-yo) commercial blends. The odor relevance of sotolon in the aroma of 3-, 5-, and 10-yo commercial blends (89 MWs) was then appraised by calculating its Odor Activity Value (OAV), after determining its content by RP-HPLC-MS/MS. The sotolon odor perception in MW was as low as 23 µg/L, although it was found that little differences in the wine matrix influenced its perception. OAVs varied between 0.1 and 22, increasing with the blend age. Considering that 16% of the OAVs are higher than 10 (mostly ≥ 10-yo), sotolon was found to be a key contributor to the overall aroma MW blends.
Introduction: Arterial hypertension is a complex, multifactorial disease, controlled by genetic a... more Introduction: Arterial hypertension is a complex, multifactorial disease, controlled by genetic and environmental factors.Objective: Evaluate the genetic susceptibility for developing arterial hypertension and its association with the traditional risk factors in the outbreak of this pathology.Material and Methods: Case-control study with 1712 individuals, mean age of 51.0 ± 7.9 years (860 hypertensive patients and 852 controls). Biochemical and traditional risk factors, and genetic variants were evaluated: ACE I/D rs4340, ACE A2350G rs4343, AGT T174M rs4762, AGT M235T rs699 AGTR1 A1166C rs5186, CYP11B2 -344 C/T rs1799998, ADRB1 R389G rs1801253, ADRB2 R16G rs1042713, ADD1 G460W rs4961, SCNN1G G173A rs5718, GNB3 C825T rs5443, ATP2B1 A/G rs2681472, CYP17A1 T/C rs11191548, SLC4A2 C/T rs2303934. The risk of each gene for hypertension was estimated by the dominant, recessive, co-dominant and multiplicative models. By logistic regression, variables associated with hypertension were evaluat...
Genetic testing and molecular biomarkers, Jan 5, 2017
Essential hypertension (EH) is a disease in which both environment and genes have an important ro... more Essential hypertension (EH) is a disease in which both environment and genes have an important role. This study was designed to identify the interaction model between genetic variants and environmental risk factors that most highly potentiates EH development. We performed a case-control study with 1641 participants (mean age 50.6 ± 8.1 years), specifically 848 patients with EH and 793 controls, adjusted for gender and age. Traditional risk factors, biochemical and genetic parameters, including the genotypic discrimination of 14 genetic variants previously associated with EH, were investigated. Multifactorial dimensionality reduction (MDR) software was used to analyze gene-environment interactions. Validation was performed using logistic regression analysis with environmental risk factors, significant genetic variants, and the best MDR model. The best model indicates that the interactions among the ADD1 rs4961 640T allele, diabetes, and obesity (body mass index ≥30) increase approxim...
Elevated levels of plasma homocysteine, an independent risk factor and a strong predictor of mort... more Elevated levels of plasma homocysteine, an independent risk factor and a strong predictor of mortality in patients with coronary artery disease (CAD), can result from nutritional deficiencies or genetic errors, including methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms. The contribution of these polymorphisms in the development of CAD remains controversial. We analysed the impact of MTHFR C677T and A1298C on fasting homocysteine and CAD in 298 CAD patients proved by angiography and 510 control subjects from the Island of Madeira (Portugal). After adjustment for other risk factors, plasma homocysteine remained independently correlated with CAD. Serum homocysteine was significantly higher in individuals with 677TT and 1298AA genotypes. There was no difference in the distribution of MTHFR677 genotypes between cases and controls but a significant increase in 1298AA prevalence was found in CAD patients. In spite of the clear effect of C677T mutation on elevated homocysteine levels we only found an association between 1298AA genotype and CAD in this population. The simultaneous presence of 677CT and 1298AA genotypes provides a significant risk of developing the disease, while the 1298AC genotype, combined with 677CC, shows a significant trend towards a decrease in CAD occurrence. The data shows an independent association between
Background Several polymorphisms within the renin-angiotensin system cluster of genes have been a... more Background Several polymorphisms within the renin-angiotensin system cluster of genes have been associated with the advent of coronary artery disease (CAD) or related pathologies. We investigated the distribution of 5 of these polymorphisms in order to find any association with CAD development and distinguish if any of the biochemical and behavioural factors interact with genetic polymorphisms in the advent of the disease. Methods ACE I/D (rs4340), ACE A11860G (rs4343), AT1R A1166C (rs5186), AGT T174M (rs4762) and AGT M235T (rs699) gene polymorphisms were PCR-RFLP analysed in 298 CAD patients and 510 controls from Portugal. Several biochemical and behavioural markers were obtained. Results ACE I/D DD and ACE11860 GG genotypes are risk factors for CAD in this population. The simultaneous presence of ACE I/D I and ACE11860 A alleles corresponds to a significant trend towards a decrease in CAD incidence. We found several synergistic effects between the studied polymorphisms and classic...
Eight microsatellite loci previously reported were assessed for their utility in parentage assign... more Eight microsatellite loci previously reported were assessed for their utility in parentage assignment in 96 individuals belonging to natural populations of the blackspot seabream Pagellus bogaraveo (Brˇnnick, 1768) from the Mediterranean and Northeast Atlantic regions. At the mtDNA level, no di¡erentiation was found between these two regions but based on microsatellite data an overall discrete genetic di¡erentiation is perceivable between the two regions separated by the Strait of Gibraltar. The number of alleles per locus ranged from 8 to 30. A database constructed with allele frequency data from six populations was used in a simulation parentage assignment test using the software CERVUS. The test showed that the number of markers used is enough to perform parentage assignments with real data. The polymorphic information content for each locus was very high (mean value of 0.849), with a total exclusionary power of 0.9995. In summary, seven of the eight microsatellites analysed proved to be su⁄cient and powerful tools for parentage assignment in hatcheries and the allele frequency data given here can be used to perform pedigree analysis against which real data may be tested.
Revista portuguesa de cardiologia : orgao oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, Jun 28, 2018
Hypertension is an important public health problem, affecting about 25% of the adult population w... more Hypertension is an important public health problem, affecting about 25% of the adult population worldwide.1 Genetic and environmental factors contribute to its pathogenesis. The T allele of the C825T polymorphism of the beta 3 subunit of G protein (rs5443) leads to the production of a truncated variant that enhances intracellular signaling and may interfere with the regulation of blood pressure. This genetic variant has been described as a risk factor for hypertension, although study results are controversial. The objective of this study was to analyze the association of the C825T polymorphism of the GNB3 gene with the occurrence of hypertension in a Portuguese population from the Madeira archipelago. A case-control study was performed with 1641 Caucasian individuals (mean age 50.6±8.1 years), 848 with hypertension and 793 controls. Blood was collected from all participants for biochemical and genetic analysis, including genotyping of the C825T polymorphism. Logistic regression anal...
After publication, the authors were alerted to ambiguous results in assaying marker 12f2. The lac... more After publication, the authors were alerted to ambiguous results in assaying marker 12f2. The lack of a distinct band defines haplogroup J lineages that can be a false-negative case when DNA is of poor quality and when using different DNA or primer concentrations. All J-chromosomes were typed using a phylogenetically equivalent binary SNP marker M304, described in:
A total of 553 Y-chromosomes were analyzed from mainland Portugal and the North Atlantic Archipel... more A total of 553 Y-chromosomes were analyzed from mainland Portugal and the North Atlantic Archipelagos of Açores and Madeira, in order to characterize the genetic composition of their male gene pool. A large majority (78-83% of each population) of the male lineages could be classified as belonging to three basic Y chromosomal haplogroups, R1b, J, and E3b. While R1b, accounting for more than half of the lineages in any of the Portuguese subpopulations, is a characteristic marker of many different West European populations, haplogroups J and E3b consist of lineages that are typical of the circum-Mediterranean region or even East Africa. The highly diverse haplogroup E3b in Portuguese likely combines sub-clades of distinct origins. The present composition of the Y chromosomes in Portugal in this haplogroup likely reflects a pre-Arab component shared with North African populations or testifies, at least in part, to the influence of Sephardic Jews. In contrast to the marginally low sub-Saharan African Y chromosome component in Portuguese, such lineages have been detected at a moderately high frequency in our previous survey of mtDNA from the same samples, indicating the presence of sex-related gene flow, most likely mediated by the Atlantic slave trade.
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