8 results on '"Maestrale GB"'
Search Results
2. Application of a new method for GWAS in a related case/control sample with known pedigree structure: identification of new loci for nephrolithiasis
- Author
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Tore S, Casula S, Casu G, Concas MP, Pistidda P, Persico I, Sassu A, Maestrale GB, Mele C, Caruso MR, Bonerba B, Usai P, Deiana I, Thornton T, Pirastu M, and Forabosco P
- Subjects
ROADTRIPS ,complex disease ,GWAS ,isolated populations ,Nephrolithiasis - Abstract
In contrast to large GWA studies based on thousands of individuals and large meta-analyses combining GWAS results, we analyzed a small case/control sample for uric acid nephrolithiasis. Our cohort of closely related individuals is derived from a small, genetically isolated village in Sardinia, with well-characterized genealogical data linking the extant population up to the 16(th) century. It is expected that the number of risk alleles involved in complex disorders is smaller in isolated founder populations than in more diverse populations, and the power to detect association with complex traits may be increased when related, homogeneous affected individuals are selected, as they are more likely to be enriched with and share specific risk variants than are unrelated, affected individuals from the general population. When related individuals are included in an association study, correlations among relatives must be accurately taken into account to ensure validity of the results. A recently proposed association method uses an empirical genotypic covariance matrix estimated from genome-screen data to allow for additional population structure and cryptic relatedness that may not be captured by the genealogical data. We apply the method to our data, and we also investigate the properties of the method, as well as other association methods, in our highly inbred population, as previous applications were to outbred samples. The more promising regions identified in our initial study in the genetic isolate were then further investigated in an independent sample collected from the Italian population. Among the loci that showed association in this study, we observed evidence of a possible involvement of the region encompassing the gene LRRC16A, already associated to serum uric acid levels in a large meta-analysis of 14 GWAS, suggesting that this locus might lead a pathway for uric acid metabolism that may be involved in gout as well as in nephrolithiasis.
- Published
- 2011
3. Combination of mutations in genes controlling DNA repair and high mutational load plays a prognostic role in pancreatic ductal adenocarcinoma (PDAC): a retrospective real-life study in Sardinian population.
- Author
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Sini MC, Doro MG, Frogheri L, Zinellu A, Paliogiannis P, Porcu A, Scognamillo F, Delogu D, Santeufemia DA, Persico I, Palomba G, Maestrale GB, Cossu A, and Palmieri G
- Subjects
- Humans, Prognosis, Retrospective Studies, Mutation genetics, DNA Repair genetics, Pancreatic Neoplasms genetics, Pancreatic Neoplasms pathology, Carcinoma, Pancreatic Ductal genetics
- Abstract
Background: Patients with pancreatic ductal adenocarcinoma (PDCA) carrying impaired mismatch repair mechanisms seem to have an outcome advantage under treatment with conventional chemotherapy, whereas the role for the tumor mutation burden on prognosis is controversial. In this study, we evaluated the prognostic role of the mutated genes involved in genome damage repair in a real-life series of PDAC patients in a hospital-based manner from the main Institution deputed to surgically treat such a disease in North Sardinia., Methods: A cohort of fifty-five consecutive PDAC patients with potentially resectable/border line resectable PDAC (stage IIB-III) or oligometastatic disease (stage IV) and tumor tissue availability underwent next-generation sequencing (NGS)-based analysis using a panel containing driver oncogenes and tumor suppressor genes as well as genes controlling DNA repair mechanisms., Results: Genes involved in the both genome damage repair (DR) and DNA mismatch repair (MMR) were found mutated in 17 (31%) and 15 (27%) cases, respectively. One fourth of PDAC cases (14/55; 25.5%) carried tumors presenting a combination of mutations in repair genes (DR and MMR) and the highest mutation load rates (MLR-H). After correction for confounders (surgery, adjuvant therapy, stage T, and metastasis), multivariate Cox regression analysis indicated that mutations in DR genes (HR = 3.0126, 95% CI 1.0707 to 8.4764, p = 0.0367) and the MLR (HR = 1.0018, 95%CI 1.0005 to 1.0032, p = 0.009) were significantly related to worse survival., Conclusions: The combination of mutated repair genes and MLR-H, which is associated with a worse survival in our series of PDAC patients treated with conventional chemotherapy protocols, might become a predictive biomarker of response to immunotherapy in addition to its prognostic role in predicting survival., (© 2024. The Author(s).)
- Published
- 2024
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4. Six Novel Loci Associated with Circulating VEGF Levels Identified by a Meta-analysis of Genome-Wide Association Studies.
- Author
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Choi SH, Ruggiero D, Sorice R, Song C, Nutile T, Vernon Smith A, Concas MP, Traglia M, Barbieri C, Ndiaye NC, Stathopoulou MG, Lagou V, Maestrale GB, Sala C, Debette S, Kovacs P, Lind L, Lamont J, Fitzgerald P, Tönjes A, Gudnason V, Toniolo D, Pirastu M, Bellenguez C, Vasan RS, Ingelsson E, Leutenegger AL, Johnson AD, DeStefano AL, Visvikis-Siest S, Seshadri S, and Ciullo M
- Subjects
- Chromosomes, Human, Gene Expression, Genome-Wide Association Study, Humans, Polymorphism, Single Nucleotide, Vascular Endothelial Growth Factor A metabolism, White People genetics, Genetic Loci, Vascular Endothelial Growth Factor A blood, Vascular Endothelial Growth Factor A genetics
- Abstract
Vascular endothelial growth factor (VEGF) is an angiogenic and neurotrophic factor, secreted by endothelial cells, known to impact various physiological and disease processes from cancer to cardiovascular disease and to be pharmacologically modifiable. We sought to identify novel loci associated with circulating VEGF levels through a genome-wide association meta-analysis combining data from European-ancestry individuals and using a dense variant map from 1000 genomes imputation panel. Six discovery cohorts including 13,312 samples were analyzed, followed by in-silico and de-novo replication studies including an additional 2,800 individuals. A total of 10 genome-wide significant variants were identified at 7 loci. Four were novel loci (5q14.3, 10q21.3, 16q24.2 and 18q22.3) and the leading variants at these loci were rs114694170 (MEF2C, P = 6.79 x 10(-13)), rs74506613 (JMJD1C, P = 1.17 x 10(-19)), rs4782371 (ZFPM1, P = 1.59 x 10(-9)) and rs2639990 (ZADH2, P = 1.72 x 10(-8)), respectively. We also identified two new independent variants (rs34528081, VEGFA, P = 1.52 x 10(-18); rs7043199, VLDLR-AS1, P = 5.12 x 10(-14)) at the 3 previously identified loci and strengthened the evidence for the four previously identified SNPs (rs6921438, LOC100132354, P = 7.39 x 10(-1467); rs1740073, C6orf223, P = 2.34 x 10(-17); rs6993770, ZFPM2, P = 2.44 x 10(-60); rs2375981, KCNV2, P = 1.48 x 10(-100)). These variants collectively explained up to 52% of the VEGF phenotypic variance. We explored biological links between genes in the associated loci using Ingenuity Pathway Analysis that emphasized their roles in embryonic development and function. Gene set enrichment analysis identified the ERK5 pathway as enriched in genes containing VEGF associated variants. eQTL analysis showed, in three of the identified regions, variants acting as both cis and trans eQTLs for multiple genes. Most of these genes, as well as some of those in the associated loci, were involved in platelet biogenesis and functionality, suggesting the importance of this process in regulation of VEGF levels. This work also provided new insights into the involvement of genes implicated in various angiogenesis related pathologies in determining circulating VEGF levels. The understanding of the molecular mechanisms by which the identified genes affect circulating VEGF levels could be important in the development of novel VEGF-related therapies for such diseases.
- Published
- 2016
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5. Bitter taste study in a sardinian genetic isolate supports the association of phenylthiocarbamide sensitivity to the TAS2R38 bitter receptor gene.
- Author
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Prodi DA, Drayna D, Forabosco P, Palmas MA, Maestrale GB, Piras D, Pirastu M, and Angius A
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- Humans, Italy, Receptors, Cell Surface physiology, Receptors, G-Protein-Coupled, Phenylthiourea pharmacology, Receptors, Cell Surface genetics, Taste genetics, Taste physiology
- Abstract
Recently, a major locus on chromosome 7q was found in association with the taste sensitivity to phenylthiocarbamide (PTC) in humans. This region contains the TAS2R38 gene that encodes a member of the TAS2R bitter taste receptor family. Three SNPs within this gene demonstrated a strong association with taster status in Utah families and in an additional sample of 85 unrelated individuals. We studied a small isolated village in eastern Sardinia and carried out a genome-wide scan to map the genetic basis of PTC perception in this population. We performed both qualitative and quantitative PTC-taste linkage analysis. Qualitative analysis was carried out by defining a cut-off from the bimodal distribution of the trait and classifying subjects as tasters and non-tasters (75 and 25%, respectively). Linkage analysis on 131 subjects belonging to a unique large multi-generation pedigree comprising 239 subjects confirmed significant evidence for linkage at 7q35 also in our population. Haplotype analyses of the three SNPs inside the PTC gene allowed us to identify only two haplotypes that were associated with the non-taster phenotype (80% AVI homozygous) and to taster phenotype (40% PAV homozygous and 56% PAV/AVI heterozygous). Sex, age and haplotype effect explained 77.2 % of the total variance in PTC sensitivity., (Copyright 2004 Oxford University Press)
- Published
- 2004
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6. A new essential hypertension susceptibility locus on chromosome 2p24-p25, detected by genomewide search.
- Author
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Angius A, Petretto E, Maestrale GB, Forabosco P, Casu G, Piras D, Fanciulli M, Falchi M, Melis PM, Palermo M, and Pirastu M
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- Chromosome Mapping, Chromosomes, Human, Pair 2, Female, Gene Frequency, Genetic Predisposition to Disease, Genotype, Humans, Hypertension epidemiology, Italy epidemiology, Male, Middle Aged, Pedigree, Hypertension genetics
- Abstract
Essential hypertension (EH) is a complex disorder that results from the interaction of a number of susceptibility genes and environmental factors. We studied an isolated Sardinian village (Talana) in which the prevalence of hypertension is comparable to that in most Western populations. Talana exhibits features, such as slow demographic growth, high inbreeding, a low number of founders, stable lifestyle and culture, and accurate genealogical records, that make it suitable for the study of complex disorders. Clinical assessment of the entire adult population (N= approximately 1,000) identified approximately 100 hypertensive subjects. For our study, we selected the individuals with the most-severe EH (i.e., diastolic blood pressure >100 mm Hg), belonging to a single deep-rooted pedigree (12 generations), whose common ancestors lived in the 17th century. We performed a three-stage genomewide search using 36 affected individuals, by means of parametric linkage and allele-sharing approaches. LOD scores >1 were observed on chromosomes 1, 2, 13, 15, 17, and 19 (stage I). The most striking result was found in a 7.57-cM region on chromosome 2p24-p25. All five nonparametric linkage statistics estimated by the SimWalk2 program lie above the significance threshold of P<.008 for the whole region. Similar significance was obtained for 2p24-25 when parametric linkage (LOD score 1.99) and linkage disequilibrium mapping (P=.00006) were used, suggesting that a hypertension-susceptibility locus is located between D2S2278 and D2S168. This finding is strengthened by a recent report of linkage with marker D2S168 in a hypertensive sib-pair sample from China.
- Published
- 2002
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7. Archival, demographic and genetic studies define a Sardinian sub-isolate as a suitable model for mapping complex traits.
- Author
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Angius A, Melis PM, Morelli L, Petretto E, Casu G, Maestrale GB, Fraumene C, Bebbere D, Forabosco P, and Pirastu M
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- Female, Gene Frequency, Genetic Markers genetics, Genetic Variation, Genetics, Population, Haplotypes, Humans, Linkage Disequilibrium genetics, Male, Microsatellite Repeats genetics, Pedigree, X Chromosome genetics, Chromosome Mapping methods, DNA, Mitochondrial genetics, Models, Genetic, Quantitative Trait, Heritable, Y Chromosome genetics
- Abstract
Genetic isolates represent exceptional resources for the mapping of complex traits but not all isolates are similar. We have selected a genetic and cultural isolate, the village of Talana from an isolated area of Sardinia, and propose that this population is suitable for the mapping of complex traits. A wealth of historical and archive data allowed the reconstruction of the demographic and genealogical history of the village. Key features of the population, which has grown slowly with no significant immigration, were defined by using a combination of historical, demographic and genetic studies. The genealogy of each Talana inhabitant was reconstructed and the main maternal and paternal lineages of the village were defined. Haplotype and phylogenetic analyses of the Y chromosome and characterisation of mitochondrial DNA haplogroups were used to determine the number of ancestral village founders. The extent of linkage disequilibrium (LD) was evaluated by the analysis of several microsatellites in chromosomal region Xq13.3, which was previously used to asses the extension of LD. Genealogical reconstructions were confirmed and reinforced by the genetic analyses, since some lineages were found to have merged prior to the beginning of the archival records, suggesting an even smaller number of founders than initially predicted. About 80% of the present-day population appears to derive from eight paternal and eleven maternal ancestral lineages. LD was found to span, on average, a 5-Mb region in Xq13.3. This suggests the possibility of identifying identical-by-descent regions associated with complex traits in a genome-wide search by using a low-density marker map. The present study emphasises the importance of combining genetic studies with genealogical and historical information.
- Published
- 2001
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8. Vanadium affects vacuolation and phosphate metabolism in Hansenula polymorpha.
- Author
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Mannazzu I, Guerra E, Strabbioli R, Masia A, Maestrale GB, Zoroddu MA, and Fatichenti F
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- Cell Division drug effects, Drug Resistance, Microbial, Magnetic Resonance Spectroscopy, Microscopy, Electron, Phosphorus Isotopes, Pichia cytology, Pichia metabolism, Vacuoles ultrastructure, Vanadates pharmacology, Phosphates metabolism, Pichia drug effects, Vacuoles drug effects, Vanadium pharmacology
- Abstract
The yeast Hansenula polymorpha is able to grow on vanadate concentrations that are toxic to other organisms. Transmission electron microscopy analysis showed that H. polymorpha cells growing on a vanadate-containing medium undergo a significant increase in cell vacuolation and a thickening of the cell wall; the presence of small cytoplasmic vesicles and an increase in cristae at the level of the plasma membrane were also observed. These ultrastructural modifications were accompanied by a change in the intracellular polyphosphate level, as shown by in vivo 31P-NMR. The involvement of these observed changes in vanadium detoxification is discussed.
- Published
- 1997
- Full Text
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