Papers by Nadiya Kazachkova
The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD)... more The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD) aimed to evaluate the psychological well-being and the familial satisfaction of subjects that 5 years prior received an unfavorable result in the predictive testing (PT). The study included 47 testees of Azorean origin (23 from the island of Flores and 24 from S. Miguel) that completed the fourth evaluation session of the MJD protocol, and undertook a neurological examination at the moment of participation in the study. Nearly 50% of testees were symptomatic at the time of the study. Psychological well-being of the 47 participants was evaluated using the Psychological General Well-Being Index (PGWB). The family satisfaction scale by adjectives was applied to obtain information on family dynamics. The average PGWB score of the total participants was of 73.3, a value indicative of psychological well-being. Nearly half of the testees presented scores indicating psychological well-being, whereas scores indicating moderate (28.9%) or severe (23.7%) stress were found in the remaining. The average score in the PGWB scale was lower in symptomatic than in asymptomatic subjects; moreover, the distinct distribution of the well-being categories seen in the two groups shows an impact of the appearance of first symptoms on the psychological state. Motives for undertaking the test, provided 5 years prior, failed to show an impact in well-being. The average score for familial satisfaction was of 134, a value compatible with high familial satisfaction, which represented the most frequent category (59.6%). Results demonstrate that well-being and family satisfaction need to be monitored in confirmed carriers of the MJD mutation. The inclusion of acceptance studies, after PT, as well as the development of acceptance training actions, should be of major importance to anticipate the possibility of psychological damage.
Background: Atherosclerosis—a major cause of vascular
disease, including ischemic heart disease (... more Background: Atherosclerosis—a major cause of vascular
disease, including ischemic heart disease (IHD), is a pathology
that has a two-fold higher mortality rate in the Azorean Islands
compared to mainland Portugal.
Aim: This cross-sectional study investigated the role of genetic
variation in the prevalence of atherosclerosis in this
population.
Subjects and methods: A total of 305 individuals were
characterized for polymorphisms in eight susceptibility genes
for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1
and APOE. Data were analysed with respect to phenotypic
characteristics such as blood pressure, lipid profile, life-style
risk factors and familial history of myocardial infarction.
Results: In the total sample, frequencies for
hypercholestrolemic, hypertensive and obese individuals were
63.6%, 39.3% and 23.3%, respectively. The genetic profile was
similar to that observed in other European populations,
namely in mainland Portugal. No over-representation of risk
alleles was evidenced in this sample.
Conclusions: One has to consider the possibility of an
important non-genetic influence on the high cholesterolemia
present in the Azorean population. Since diet is the most
important life-style risk factor for dyslipidemia, studies aiming
to evaluate the dietary characteristics of this population and
its impact on serum lipid levels will be of major importance.
Objective: To investigate a modulating effect of the apolipoprotein
E (APOE) polymorphism on age ... more Objective: To investigate a modulating effect of the apolipoprotein
E (APOE) polymorphism on age at onset of
Machado-Joseph disease (MJD).
Design: We collected blood samples from 192 patients
with MJD and typed the APOE polymorphism.
Patients: The 192 patients with MJD included 59 from
the Azores, 73 from mainland Portugal, and 60 from
Brazil.
Setting: Academic research center.
Results: Cases with the ε2/ε3 genotype had an earlier
onset compared with those with the ε3/ε3 or the ε3/ε4
genotype. In this series of patients, the presence of an
APOE ε2 allele implies a decrease of nearly 5 years in the
age at onset. When combining several other predictors
in a general linear model, namely, the presence/absence
of the APOE ε2 allele, with the size of the (CAG)n in expanded
alleles, the modelwas significantly improved and
the explanation of onset variance was raised from 59.8%
to 66.5%. Furthermore, the presence of the ε2 allele was
associated with an onset before age 39 years (odds ratio,
5.00; 95% CI, 1.18-21.14).
Conclusion: The polymorphism at the APOE gene plays
a role as a genetic modifier of MJD phenotype.
Machado–Joseph disease (MJD) is a late-onset autosomal dominant neurodegenerative disorder, which... more Machado–Joseph disease (MJD) is a late-onset autosomal dominant neurodegenerative disorder, which is caused by a coding (CAG) n expansion in the ATXN3 gene (14q32.1). The number of CAG repeats in the expanded alleles accounts only for 50 to 75 % of onset variance, the remaining variation being dependent on other factors. Differential allelic expression of ATXN3 could contribute to the explanation of different ages at onset in patients displaying similar CAG repeat sizes. Variation in 5′ regulatory regions of
the ATXN3 gene may have the potential to influence expression
levels and, ultimately, modulate the MJD phenotype. The main
goal of this work was to analyze the extent of sequence variation
upstream of the ATXN3 start codon. A fragment containing
the core promoter and the 5′ untranslated region (UTR) was
sequenced and analyzed in 186 patients and 59 controls (490
chromosomes). In the core promoter, no polymorphisms were
observed. In the 5′ UTR, only one SNP (rs3814834) was found,
but no improvements on the explanation of onset variance were
observed, when adding its allelic state in a linear model. Accordingly,
in silico analysis predicted that this SNP lays in a
nonconserved position for CMYB binding. Therefore, no functional
effect could be predicted for this variant.
A significant body of work, accumulated over the years, strongly suggests that damage in mitochon... more A significant body of work, accumulated over the years, strongly suggests that damage in mitochondrial DNA (mtDNA) contributes to aging in humans. Contradictory results, however, are reported in the literature, with some studies failing to provide support to this hypothesis. With the purpose of further understanding the aging process, several models, among which mouse models, have been frequently used. Although important affinities are recognized between humans and mice, differences on what concerns physiological properties, disease pathogenesis as well as life-history exist between the two; the extent to which such differences limit the translation, from mice to humans, of insights on the association between mtDNA damage and aging remains to be established. In this paper we revise the studies that analyze the association between patterns of mtDNA damage and aging, investigating putative alterations in mtDNA copy number as well as accumulation of deletions and of point mutations. Reports from the literature do not allow the establishment of a clear association between mtDNA copy number and age, either in humans or in mice. Further analysis, using a wide spectrum of tissues and a high number of individuals would be necessary to elucidate this pattern. Likewise humans, mice demonstrated a clear pattern of age-dependent and tissue-specific accumulation of mtDNA deletions. Deletions increase with age, and the highest amount of deletions has been observed in brain tissues both in humans and mice. On the other hand, mtDNA point mutations accumulation has been clearly associated with age in humans, but not in mice. Although further studies, using the same methodologies and targeting a larger number of samples would be mandatory to draw definitive conclusions, the revision of the available data raises concerns on the ability of mouse models to mimic the mtDNA damage patterns of humans, a fact with implications not only for the study of the aging process, but also for investigations of other processes in which mtDNA dysfunction is a hallmark, such as neurodegeneration.
Familial hypercholesterolemia (FH) is an autosomal dominant disorder
of the cholesterol metabolis... more Familial hypercholesterolemia (FH) is an autosomal dominant disorder
of the cholesterol metabolism, which constitutes a risk factor for
coronary arterial disease (CAD). In the Azores Islands (Portugal),
where mortality from CAD doubles its rate comparatively to the rest of
the country and where a high frequency of dyslipidemia has been
reported, the prevalence and distribution of FH remain unknown. The
molecular characterization of a group of 33 possible cases of FH of
Azorean background was undertaken in this study. A DNA array was
initially used to search mutations in the LDLR, APOB and PCSK9 loci in
10 unrelated possible cases of FH. No mutations were detected in the
array; after sequencing the full LDLR gene, 18 variants were identified,
corresponding to two missense (c.806G > A; c.1171G > A) and sixteen
synonymous alterations. Six of the synonymous variants which are consistently described in the literature as associated with altered cholesterol levels were used to build haplotypes. The most frequent haplotype corresponded to TTCGCC (45%), a “risk” haplotype, formed
exclusively by alleles that were reported to increase cholesterol levels.
Some of the variants detected in the full sequencing of the LDLR gene
fell within the ligand-binding domain of this gene, defined by exons 2
to 6. To add information as to the role of such variants, these exons
were sequenced in the remaining 23 possible FH cases. Two missense
alterations (c.185C > T; c.806G > A) were found in this subset of
possible FH cases. The missense alteration c.185C > T, identified in one
individual, is novel for the Portuguese population. In silico analysis was
not conclusive for this alteration, whose role will have to be further
investigated. This study represents the first approach to the establishment
of the mutational profile of FH in the Azores Islands.
Mitochondrial dysfunction has been associated with late onset neurodegenerative disorders, among ... more Mitochondrial dysfunction has been associated with late onset neurodegenerative disorders, among which is Machado–Joseph disease (MJD/SCA3). In a previous study, using a transgenic mouse model of MJD, we reported a decrease in mitochondrial DNA (mtDNA) copy number and an accumulation of the 3876-bp deletion with age and with phenotype development. We extended this study by analyzing the pattern of mtDNA depletion and the accumulation of the 3876-bp deletion in 12 older transgenic (TG) and 4 wild-type (wt) animals, and by investigating the accumulation of somatic mutations in the D-loop region in 76 mice (42 TG and 34 wt). mtDNA damage was studied in TG and wt mice at different ages and tissues (blood, pontine nuclei, and hippocampus). Results for older mice demonstrate an accumulation of the mtDNA 3867-bp deletion with age, which was more pronounced in TG animals. Furthermore, the tendency for mtDNA copy number decrease with age, in all analyzed tissues of TG and wt animals, was also confirmed. No point mutations were detected in the D-loop, neither in TG nor wt animals, in any of the tissues analyzed. Due to the absence of mtDNA somatic mutations, we can suggest that mtDNA point mutation accumulation cannot be used to monitor the development and progression of the phenotype in this mouse model and likely in any MJD mice model. The present results further confirm not only the association between mtDNA alterations (copy number and deletions) and age, but also between such alterations and the expression of the mutant ataxin-3 in TG mice.
Machado-Joseph disease (or spinocerebellar
ataxia type 3) is a late-onset polyglutamine
neurodege... more Machado-Joseph disease (or spinocerebellar
ataxia type 3) is a late-onset polyglutamine
neurodegenerative disorder caused by a mutation in the
ATXN3 gene, which encodes for the ubiquitously
expressed protein ataxin-3. Previous studies on cell and
animal models have suggested that mutated ataxin-3 is
involved in transcriptional dysregulation. Starting with a
whole-transcriptome profiling of peripheral blood samples
from patients and controls, we aimed to confirm abnormal
expression profiles in Machado-Joseph disease and to
identify promising up-regulated genes as potential candidate
biomarkers of disease status. The Illumina Human
V4-HT12 array was used to measure transcriptome-wide
gene expression in peripheral blood samples from 12
patients and 12 controls. Technical validation and validation
in an independent set of samples were performed by
quantitative real-time polymerase chain reaction (PCR).
Based on the results from the microarray, twenty six
genes, found to be up-regulated in patients, were
selected for technical validation by quantitative real-time
PCR (validation rate of 81% for the up-regulation trend).
Fourteen of these were further tested in an independent
set of 42 patients and 35 controls; 10 genes maintained
the up-regulation trend (FCGR3B, CSR2RA, CLC,
TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and
GPR96); FCGR3B, P2RY13, and SELPLG were significantly
up-regulated in patients when compared with controls.
Our findings support the hypothesis that mutated
ataxin-3 is associated with transcription dysregulation,
detectable in peripheral blood cells. Furthermore, this is
the first report suggesting a pool of up-regulated genes in
Machado-Joseph disease that may have the potential to
be used for fine phenotyping of this disease.VC 2015 International Parkinson and Movement Disorder Society
Key Words: spinocerebellar ataxia type 3; polyglutamine
disease; gene expression; ataxin-3; microarray
The pollen beetle (Meligethes aeneus) is one of the most important insect pests of oilseed rape (... more The pollen beetle (Meligethes aeneus) is one of the most important insect pests of oilseed rape (Brassica napus), and
extensive use of insecticides is required to protect crop yields. To meet the challenges set by agricultural demands for more sustainable
production and changing climate more information about pest biology and population genetics is needed. Using genomic
Amplified Fragment Length Polymorphism (AFLP) analysis, DNA polymorphism was studied in 14 field populations of pollen beetles,
collected during 2004 in six European countries (Denmark, France, Finland, Germany, Sweden, and UK). Using one primer
combination 410 polymorphic DNA fragments were obtained based on analysis of single beetles. AFLP profiles were analysed with
similarity measures using the Nei and Li coefficient and dendrograms generated. Dendrograms constructed from distance matrices
revealed clustering by population origin and assignment analysis generally supported the genotype classification. Principal component
analysis of the fourteen groups resulted in wide dispersion but also connections between some groups. Statistical analysis using
AMOVA showed that the levels of genetic variation within populations explained most of the variation. Migrant analysis suggested
a low level of gene flow between pollen beetle populations at different geographical locations indicating little long range dispersal of
pollen beetles. However, a Mantel test found no correlation between genetic and geographical distance. Apparently genetic differentiation
among populations has a complex background and may involve factors such as local adaptation and founder effects.
Page 1. Genotype Analysis and Studies of Pyrethroid Resistance of the Oilseed Rape (Brassica napu... more Page 1. Genotype Analysis and Studies of Pyrethroid Resistance of the Oilseed Rape (Brassica napus) Insect Pest - Pollen Beetle (Meligethes aeneus) NI Kazachkova Faculty of Natural Resources and Agricultural Sciences ...
Differences in the presence of diseases, their frequency and associated health outcomes are obser... more Differences in the presence of diseases, their frequency and associated health outcomes are observed in many world populations. The knowledge relative to the genetic variants underlying diseases, namely the characterization of their distribution in the various populations, as well as the analysis of the factors which control this distribution are, therefore, of great importance. We have revised the population studies performed for disease-associated loci in the Portuguese population and organized a novel database, currently being concluded, produced from this extensive revision of the literature. The revision covered reports on 126 distinct genetic diseases, including 78 monogenic and 48 multifactorial. Among monogenic diseases 30 (38.46%) are autosomal dominant, 38 (48.72%) are autosomal recessive, 3 (3.85%) are X-linked dominant, 5 (6.41%) are X-linked recessive and 2 (2.56%) are mitochondrial. Diseases of the nervous system (19 of 126, 15.01%), neoplasms (28 of 126, 22.12%) and e...
A Hipercolesterolemia Familiar (HF) é uma patologia autossómica dominante que afecta, mundialment... more A Hipercolesterolemia Familiar (HF) é uma patologia autossómica dominante que afecta, mundialmente, 1 em cada 500 indivíduos, pelo que é uma das doenças monogénicas mais comuns. A HF é causada, na maioria dos casos, por mutações no gene receptor das lipoproteínas de baixa densidade (LDLR), provocando um aumento dos níveis de colesterol-LDL no soro, e conduzindo à aterosclerose e à doença coronária prematura. No arquipélago dos Açores, desconhece-se a preva-lência e distribuição da HF; o objectivo deste estudo-piloto foi proceder à análise do gene LDLR, mais especificamente dos exões 2 a 6, que codificam um impor-tante domínio funcional do receptor-LDL, associado à ocorrência de endocitose da lipoproteína LDL pelo fígado. Os exões 2 a 6 do gene LDLRforam amplificados por PCR e posteriormente sequenciados. No total, foram estudados 33 possíveis casos de HF, 10 homens (30,3%) e 23 mulheres (69,7%), que foram seleccionados de acordo com os critérios adaptados de Simon Broome Heart Resea...
Heterozygous familial hypercholesterolemia (FH) is an autosomal dominant inherited disorder that ... more Heterozygous familial hypercholesterolemia (FH) is an autosomal dominant inherited disorder that affects approximately 1 in 500 individuals worldwide, which makes it one of the most common monogenic pathologies. FH is caused mainly by mutations in the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB) and Proprotein convertase subtilisin/kexin type 9 (PCSK9) genes, causing an increase in LDL cholesterol levels in serum, and leading to atherosclerosis and premature coronary heart disease. In the Azores archipelago, where the mortality rate for ischemic heart disease doubles its rate comparatively to the rest of the country, the prevalence and distribution of FH remains unknown. In this work a series of 10 probable FH patients of Azorean origin (7 women and 3 men) previously identified using the criteria adapted from the Simon Broome Heart Research Trust was analyzed. The Lipochip Array (Progenika, Derio, Spain) a microarray that screens 207 mutations in the LDLR, 3 majo...
Open Journal of Genetics, 2011
Background: Atherosclerosis and thrombosis are the major manifestations underlying cardiovascular... more Background: Atherosclerosis and thrombosis are the major manifestations underlying cardiovascular diseases (CVD), which are the leading cause of mortality and morbidity worldwide. Both result from an interaction between genetic and environmental risk factors. The goal of our study was to evaluate several polymorphisms identified as predisposing factors to atherosclerosis and thrombosis. Material and Methods: A series of 155 healthy unrelated individuals of Azorean origin were analyzed using the CVD StripAssay (ViennaLab Diagnostics, Austria) for the most established polymorphisms involved in blood coagulation , fibrinolitic system (SERPINE1), platelet adhesion (ITGB3), homocysteine metabolism (MTHFR), reninangiotensin system (ACE) and lipid metabolism (APOE). Results: No significant differences were observed in allelic frequencies when comparing our data to mainland Portugal. Group stratification according to the number of "increased" risk alleles, demonstrated that 116/155 (75%) individuals belong to the moderate risk group (5 -10 risk alleles). Conclusions: Although acknowledging the fact that the allelic states at the analysed loci lack predictive value, the fact that a high frequency of individuals presents at least 5 risk alleles (124/155; 80%) is important for the establishment of the appropriate preventive measures in the Azorean population.
Neurodegenerative Diseases, 2013
damage was studied by fluorescence-based quantitative PCR in 84 transgenic and 93 wild-type sampl... more damage was studied by fluorescence-based quantitative PCR in 84 transgenic and 93 wild-type samples. Results: A clear pattern of decrease in mtDNA copy number with age and accumulation of 3,867-bp deletions at the initial stages (both being more pronounced in transgenic mice) was observed. Pontine nuclei, the affected tissue in transgenic mice, displayed 1.5 times less copies of mtDNA than nonaffected brain tissue hippocampus (odds ratio = 1.21). Pontine nuclei displayed the highest percentage of mtDNA deletions (6.05% more in transgenic mice). Conclusion: These results suggest that mtDNA damage is related to the initiation of the phenotype in transgenic mice; mtDNA 3,867-bp deletions may be a biomarker of the initial stages of the disease.
Genetic Testing and Molecular Biomarkers, 2012
The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD)... more The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD) aimed to evaluate the psychological well-being and the familial satisfaction of subjects that 5 years prior received an unfavorable result in the predictive testing (PT). The study included 47 testees of Azorean origin (23 from the island of Flores and 24 from S. Miguel) that completed the fourth evaluation session of the MJD protocol, and undertook a neurological examination at the moment of participation in the study. Nearly 50% of testees were symptomatic at the time of the study. Psychological well-being of the 47 participants was evaluated using the Psychological General Well-Being Index (PGWB). The family satisfaction scale by adjectives was applied to obtain information on family dynamics. The average PGWB score of the total participants was of 73.3, a value indicative of psychological well-being. Nearly half of the testees presented scores indicating psychological wellbeing, whereas scores indicating moderate (28.9%) or severe (23.7%) stress were found in the remaining. The average score in the PGWB scale was lower in symptomatic than in asymptomatic subjects; moreover, the distinct distribution of the well-being categories seen in the two groups shows an impact of the appearance of first symptoms on the psychological state. Motives for undertaking the test, provided 5 years prior, failed to show an impact in well-being. The average score for familial satisfaction was of 134, a value compatible with high familial satisfaction, which represented the most frequent category (59.6%). Results demonstrate that wellbeing and family satisfaction need to be monitored in confirmed carriers of the MJD mutation. The inclusion of acceptance studies, after PT, as well as the development of acceptance training actions, should be of major importance to anticipate the possibility of psychological damage.
Genetic Testing and Molecular Biomarkers, 2012
The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD)... more The present study on long-term outcome of presymptomatic testing for Machado-Joseph disease (MJD) aimed to evaluate the psychological well-being and the familial satisfaction of subjects that 5 years prior received an unfavorable result in the predictive testing (PT). The study included 47 testees of Azorean origin (23 from the island of Flores and 24 from S. Miguel) that completed the fourth evaluation session of the MJD protocol, and undertook a neurological examination at the moment of participation in the study. Nearly 50% of testees were symptomatic at the time of the study. Psychological well-being of the 47 participants was evaluated using the Psychological General Well-Being Index (PGWB). The family satisfaction scale by adjectives was applied to obtain information on family dynamics. The average PGWB score of the total participants was of 73.3, a value indicative of psychological well-being. Nearly half of the testees presented scores indicating psychological wellbeing, whereas scores indicating moderate (28.9%) or severe (23.7%) stress were found in the remaining. The average score in the PGWB scale was lower in symptomatic than in asymptomatic subjects; moreover, the distinct distribution of the well-being categories seen in the two groups shows an impact of the appearance of first symptoms on the psychological state. Motives for undertaking the test, provided 5 years prior, failed to show an impact in well-being. The average score for familial satisfaction was of 134, a value compatible with high familial satisfaction, which represented the most frequent category (59.6%). Results demonstrate that wellbeing and family satisfaction need to be monitored in confirmed carriers of the MJD mutation. The inclusion of acceptance studies, after PT, as well as the development of acceptance training actions, should be of major importance to anticipate the possibility of psychological damage.
Journal of Molecular Neuroscience, 2014
Mitochondrial dysfunction has been associated with late onset neurodegenerative disorders, among ... more Mitochondrial dysfunction has been associated with late onset neurodegenerative disorders, among which is Machado-Joseph disease (MJD/SCA3). In a previous study, using a transgenic mouse model of MJD, we reported a decrease in mitochondrial DNA (mtDNA) copy number and an accumulation of the 3876-bp deletion with age and with phenotype development. We extended this study by analyzing the pattern of mtDNA depletion and the accumulation of the 3876bp deletion in 12 older transgenic (TG) and 4 wild-type (wt) animals, and by investigating the accumulation of somatic mutations in the D-loop region in 76 mice (42 TG and 34 wt). mtDNA damage was studied in TG and wt mice at different ages and tissues (blood, pontine nuclei, and hippocampus). Results for older mice demonstrate an accumulation of the mtDNA 3867-bp deletion with age, which was more pronounced in TG animals. Furthermore, the tendency for mtDNA copy number decrease with age, in all analyzed tissues of TG and wt animals, was also confirmed. No point mutations were detected in the D-loop, neither in TG nor wt animals, in any of the tissues analyzed. Due to the absence of mtDNA somatic mutations, we can suggest that mtDNA point mutation accumulation cannot be used to monitor the development and progression of the phenotype in this mouse model and likely in any MJD mice model. The present results further confirm not only the association between mtDNA alterations (copy number and deletions) and age, but also between such alterations and the expression of the mutant ataxin-3 in TG mice.
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Papers by Nadiya Kazachkova
disease, including ischemic heart disease (IHD), is a pathology
that has a two-fold higher mortality rate in the Azorean Islands
compared to mainland Portugal.
Aim: This cross-sectional study investigated the role of genetic
variation in the prevalence of atherosclerosis in this
population.
Subjects and methods: A total of 305 individuals were
characterized for polymorphisms in eight susceptibility genes
for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1
and APOE. Data were analysed with respect to phenotypic
characteristics such as blood pressure, lipid profile, life-style
risk factors and familial history of myocardial infarction.
Results: In the total sample, frequencies for
hypercholestrolemic, hypertensive and obese individuals were
63.6%, 39.3% and 23.3%, respectively. The genetic profile was
similar to that observed in other European populations,
namely in mainland Portugal. No over-representation of risk
alleles was evidenced in this sample.
Conclusions: One has to consider the possibility of an
important non-genetic influence on the high cholesterolemia
present in the Azorean population. Since diet is the most
important life-style risk factor for dyslipidemia, studies aiming
to evaluate the dietary characteristics of this population and
its impact on serum lipid levels will be of major importance.
E (APOE) polymorphism on age at onset of
Machado-Joseph disease (MJD).
Design: We collected blood samples from 192 patients
with MJD and typed the APOE polymorphism.
Patients: The 192 patients with MJD included 59 from
the Azores, 73 from mainland Portugal, and 60 from
Brazil.
Setting: Academic research center.
Results: Cases with the ε2/ε3 genotype had an earlier
onset compared with those with the ε3/ε3 or the ε3/ε4
genotype. In this series of patients, the presence of an
APOE ε2 allele implies a decrease of nearly 5 years in the
age at onset. When combining several other predictors
in a general linear model, namely, the presence/absence
of the APOE ε2 allele, with the size of the (CAG)n in expanded
alleles, the modelwas significantly improved and
the explanation of onset variance was raised from 59.8%
to 66.5%. Furthermore, the presence of the ε2 allele was
associated with an onset before age 39 years (odds ratio,
5.00; 95% CI, 1.18-21.14).
Conclusion: The polymorphism at the APOE gene plays
a role as a genetic modifier of MJD phenotype.
the ATXN3 gene may have the potential to influence expression
levels and, ultimately, modulate the MJD phenotype. The main
goal of this work was to analyze the extent of sequence variation
upstream of the ATXN3 start codon. A fragment containing
the core promoter and the 5′ untranslated region (UTR) was
sequenced and analyzed in 186 patients and 59 controls (490
chromosomes). In the core promoter, no polymorphisms were
observed. In the 5′ UTR, only one SNP (rs3814834) was found,
but no improvements on the explanation of onset variance were
observed, when adding its allelic state in a linear model. Accordingly,
in silico analysis predicted that this SNP lays in a
nonconserved position for CMYB binding. Therefore, no functional
effect could be predicted for this variant.
of the cholesterol metabolism, which constitutes a risk factor for
coronary arterial disease (CAD). In the Azores Islands (Portugal),
where mortality from CAD doubles its rate comparatively to the rest of
the country and where a high frequency of dyslipidemia has been
reported, the prevalence and distribution of FH remain unknown. The
molecular characterization of a group of 33 possible cases of FH of
Azorean background was undertaken in this study. A DNA array was
initially used to search mutations in the LDLR, APOB and PCSK9 loci in
10 unrelated possible cases of FH. No mutations were detected in the
array; after sequencing the full LDLR gene, 18 variants were identified,
corresponding to two missense (c.806G > A; c.1171G > A) and sixteen
synonymous alterations. Six of the synonymous variants which are consistently described in the literature as associated with altered cholesterol levels were used to build haplotypes. The most frequent haplotype corresponded to TTCGCC (45%), a “risk” haplotype, formed
exclusively by alleles that were reported to increase cholesterol levels.
Some of the variants detected in the full sequencing of the LDLR gene
fell within the ligand-binding domain of this gene, defined by exons 2
to 6. To add information as to the role of such variants, these exons
were sequenced in the remaining 23 possible FH cases. Two missense
alterations (c.185C > T; c.806G > A) were found in this subset of
possible FH cases. The missense alteration c.185C > T, identified in one
individual, is novel for the Portuguese population. In silico analysis was
not conclusive for this alteration, whose role will have to be further
investigated. This study represents the first approach to the establishment
of the mutational profile of FH in the Azores Islands.
ataxia type 3) is a late-onset polyglutamine
neurodegenerative disorder caused by a mutation in the
ATXN3 gene, which encodes for the ubiquitously
expressed protein ataxin-3. Previous studies on cell and
animal models have suggested that mutated ataxin-3 is
involved in transcriptional dysregulation. Starting with a
whole-transcriptome profiling of peripheral blood samples
from patients and controls, we aimed to confirm abnormal
expression profiles in Machado-Joseph disease and to
identify promising up-regulated genes as potential candidate
biomarkers of disease status. The Illumina Human
V4-HT12 array was used to measure transcriptome-wide
gene expression in peripheral blood samples from 12
patients and 12 controls. Technical validation and validation
in an independent set of samples were performed by
quantitative real-time polymerase chain reaction (PCR).
Based on the results from the microarray, twenty six
genes, found to be up-regulated in patients, were
selected for technical validation by quantitative real-time
PCR (validation rate of 81% for the up-regulation trend).
Fourteen of these were further tested in an independent
set of 42 patients and 35 controls; 10 genes maintained
the up-regulation trend (FCGR3B, CSR2RA, CLC,
TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and
GPR96); FCGR3B, P2RY13, and SELPLG were significantly
up-regulated in patients when compared with controls.
Our findings support the hypothesis that mutated
ataxin-3 is associated with transcription dysregulation,
detectable in peripheral blood cells. Furthermore, this is
the first report suggesting a pool of up-regulated genes in
Machado-Joseph disease that may have the potential to
be used for fine phenotyping of this disease.VC 2015 International Parkinson and Movement Disorder Society
Key Words: spinocerebellar ataxia type 3; polyglutamine
disease; gene expression; ataxin-3; microarray
extensive use of insecticides is required to protect crop yields. To meet the challenges set by agricultural demands for more sustainable
production and changing climate more information about pest biology and population genetics is needed. Using genomic
Amplified Fragment Length Polymorphism (AFLP) analysis, DNA polymorphism was studied in 14 field populations of pollen beetles,
collected during 2004 in six European countries (Denmark, France, Finland, Germany, Sweden, and UK). Using one primer
combination 410 polymorphic DNA fragments were obtained based on analysis of single beetles. AFLP profiles were analysed with
similarity measures using the Nei and Li coefficient and dendrograms generated. Dendrograms constructed from distance matrices
revealed clustering by population origin and assignment analysis generally supported the genotype classification. Principal component
analysis of the fourteen groups resulted in wide dispersion but also connections between some groups. Statistical analysis using
AMOVA showed that the levels of genetic variation within populations explained most of the variation. Migrant analysis suggested
a low level of gene flow between pollen beetle populations at different geographical locations indicating little long range dispersal of
pollen beetles. However, a Mantel test found no correlation between genetic and geographical distance. Apparently genetic differentiation
among populations has a complex background and may involve factors such as local adaptation and founder effects.
disease, including ischemic heart disease (IHD), is a pathology
that has a two-fold higher mortality rate in the Azorean Islands
compared to mainland Portugal.
Aim: This cross-sectional study investigated the role of genetic
variation in the prevalence of atherosclerosis in this
population.
Subjects and methods: A total of 305 individuals were
characterized for polymorphisms in eight susceptibility genes
for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1
and APOE. Data were analysed with respect to phenotypic
characteristics such as blood pressure, lipid profile, life-style
risk factors and familial history of myocardial infarction.
Results: In the total sample, frequencies for
hypercholestrolemic, hypertensive and obese individuals were
63.6%, 39.3% and 23.3%, respectively. The genetic profile was
similar to that observed in other European populations,
namely in mainland Portugal. No over-representation of risk
alleles was evidenced in this sample.
Conclusions: One has to consider the possibility of an
important non-genetic influence on the high cholesterolemia
present in the Azorean population. Since diet is the most
important life-style risk factor for dyslipidemia, studies aiming
to evaluate the dietary characteristics of this population and
its impact on serum lipid levels will be of major importance.
E (APOE) polymorphism on age at onset of
Machado-Joseph disease (MJD).
Design: We collected blood samples from 192 patients
with MJD and typed the APOE polymorphism.
Patients: The 192 patients with MJD included 59 from
the Azores, 73 from mainland Portugal, and 60 from
Brazil.
Setting: Academic research center.
Results: Cases with the ε2/ε3 genotype had an earlier
onset compared with those with the ε3/ε3 or the ε3/ε4
genotype. In this series of patients, the presence of an
APOE ε2 allele implies a decrease of nearly 5 years in the
age at onset. When combining several other predictors
in a general linear model, namely, the presence/absence
of the APOE ε2 allele, with the size of the (CAG)n in expanded
alleles, the modelwas significantly improved and
the explanation of onset variance was raised from 59.8%
to 66.5%. Furthermore, the presence of the ε2 allele was
associated with an onset before age 39 years (odds ratio,
5.00; 95% CI, 1.18-21.14).
Conclusion: The polymorphism at the APOE gene plays
a role as a genetic modifier of MJD phenotype.
the ATXN3 gene may have the potential to influence expression
levels and, ultimately, modulate the MJD phenotype. The main
goal of this work was to analyze the extent of sequence variation
upstream of the ATXN3 start codon. A fragment containing
the core promoter and the 5′ untranslated region (UTR) was
sequenced and analyzed in 186 patients and 59 controls (490
chromosomes). In the core promoter, no polymorphisms were
observed. In the 5′ UTR, only one SNP (rs3814834) was found,
but no improvements on the explanation of onset variance were
observed, when adding its allelic state in a linear model. Accordingly,
in silico analysis predicted that this SNP lays in a
nonconserved position for CMYB binding. Therefore, no functional
effect could be predicted for this variant.
of the cholesterol metabolism, which constitutes a risk factor for
coronary arterial disease (CAD). In the Azores Islands (Portugal),
where mortality from CAD doubles its rate comparatively to the rest of
the country and where a high frequency of dyslipidemia has been
reported, the prevalence and distribution of FH remain unknown. The
molecular characterization of a group of 33 possible cases of FH of
Azorean background was undertaken in this study. A DNA array was
initially used to search mutations in the LDLR, APOB and PCSK9 loci in
10 unrelated possible cases of FH. No mutations were detected in the
array; after sequencing the full LDLR gene, 18 variants were identified,
corresponding to two missense (c.806G > A; c.1171G > A) and sixteen
synonymous alterations. Six of the synonymous variants which are consistently described in the literature as associated with altered cholesterol levels were used to build haplotypes. The most frequent haplotype corresponded to TTCGCC (45%), a “risk” haplotype, formed
exclusively by alleles that were reported to increase cholesterol levels.
Some of the variants detected in the full sequencing of the LDLR gene
fell within the ligand-binding domain of this gene, defined by exons 2
to 6. To add information as to the role of such variants, these exons
were sequenced in the remaining 23 possible FH cases. Two missense
alterations (c.185C > T; c.806G > A) were found in this subset of
possible FH cases. The missense alteration c.185C > T, identified in one
individual, is novel for the Portuguese population. In silico analysis was
not conclusive for this alteration, whose role will have to be further
investigated. This study represents the first approach to the establishment
of the mutational profile of FH in the Azores Islands.
ataxia type 3) is a late-onset polyglutamine
neurodegenerative disorder caused by a mutation in the
ATXN3 gene, which encodes for the ubiquitously
expressed protein ataxin-3. Previous studies on cell and
animal models have suggested that mutated ataxin-3 is
involved in transcriptional dysregulation. Starting with a
whole-transcriptome profiling of peripheral blood samples
from patients and controls, we aimed to confirm abnormal
expression profiles in Machado-Joseph disease and to
identify promising up-regulated genes as potential candidate
biomarkers of disease status. The Illumina Human
V4-HT12 array was used to measure transcriptome-wide
gene expression in peripheral blood samples from 12
patients and 12 controls. Technical validation and validation
in an independent set of samples were performed by
quantitative real-time polymerase chain reaction (PCR).
Based on the results from the microarray, twenty six
genes, found to be up-regulated in patients, were
selected for technical validation by quantitative real-time
PCR (validation rate of 81% for the up-regulation trend).
Fourteen of these were further tested in an independent
set of 42 patients and 35 controls; 10 genes maintained
the up-regulation trend (FCGR3B, CSR2RA, CLC,
TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and
GPR96); FCGR3B, P2RY13, and SELPLG were significantly
up-regulated in patients when compared with controls.
Our findings support the hypothesis that mutated
ataxin-3 is associated with transcription dysregulation,
detectable in peripheral blood cells. Furthermore, this is
the first report suggesting a pool of up-regulated genes in
Machado-Joseph disease that may have the potential to
be used for fine phenotyping of this disease.VC 2015 International Parkinson and Movement Disorder Society
Key Words: spinocerebellar ataxia type 3; polyglutamine
disease; gene expression; ataxin-3; microarray
extensive use of insecticides is required to protect crop yields. To meet the challenges set by agricultural demands for more sustainable
production and changing climate more information about pest biology and population genetics is needed. Using genomic
Amplified Fragment Length Polymorphism (AFLP) analysis, DNA polymorphism was studied in 14 field populations of pollen beetles,
collected during 2004 in six European countries (Denmark, France, Finland, Germany, Sweden, and UK). Using one primer
combination 410 polymorphic DNA fragments were obtained based on analysis of single beetles. AFLP profiles were analysed with
similarity measures using the Nei and Li coefficient and dendrograms generated. Dendrograms constructed from distance matrices
revealed clustering by population origin and assignment analysis generally supported the genotype classification. Principal component
analysis of the fourteen groups resulted in wide dispersion but also connections between some groups. Statistical analysis using
AMOVA showed that the levels of genetic variation within populations explained most of the variation. Migrant analysis suggested
a low level of gene flow between pollen beetle populations at different geographical locations indicating little long range dispersal of
pollen beetles. However, a Mantel test found no correlation between genetic and geographical distance. Apparently genetic differentiation
among populations has a complex background and may involve factors such as local adaptation and founder effects.