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Genetic Susceptibility Factor (genetic + susceptibility_factor)
Selected AbstractsThe role of tau (MAPT) in frontotemporal dementia and related tauopathies,HUMAN MUTATION, Issue 4 2004R. Rademakers Abstract Tau is a multifunctional protein that was originally identified as a microtubule-associated protein. In patients diagnosed with frontotemporal dementia and parkinsonism linked to chromosome 17, mutations in the gene encoding tau (MAPT) have been identified that disrupt the normal binding of tau to tubulin resulting in pathological deposits of hyperphosphorylated tau. Abnormal filamentous tau deposits have been reported as a pathological characteristic in several other neurodegenerative diseases, including frontotemporal dementia, Pick Disease, Alzheimer disease, argyrophilic grain disease, progressive supranuclear palsy, and corticobasal degeneration. In the last five years, extensive research has identified 34 different pathogenic MAPT mutations in 101 families worldwide. In vitro, cell-free and transfected cell studies have provided valuable information on tau dysfunction and transgenic mice carrying human MAPT mutations are being generated to study the influence of MAPT mutations in vivo. This mutation update describes the considerable differences in clinical and pathological presentation of patients with MAPT mutations and summarizes the effect of the different mutations on tau functioning. In addition, the role of tau as a genetic susceptibility factor is discussed, together with the genetic evidence for additional causal genes for tau-positive as well as tau-negative dementia. Hum Mutat 24:277,295, 2004. © 2004 Wiley-Liss, Inc. [source] Etiopathogenic role of HLA-B27 alleles in ankylosing spondylitisINTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 3 2005Nurullah AKKOC Abstract HLA-B27 is the major genetic susceptibility factor for ankylosing spondylitis (AS). However, its precise role in the pathogenesis of AS still remains unclear, even though its gene has been cloned and sequenced, and its crystallographic structure has been defined. Arthritogenic peptide and molecular mimicry hypotheses propose mechanisms related to an antigen-presenting function of HLA-B27 to be responsible for disease development. However, peculiar aspects of its immunobiology, such as its misfolding and heavy chain dimerization raise the possibility of involvement of pathogenic mechanisms unrelated to its physiological function. Moreover, HLA-B27 is not a single allele, but a family of 31 different alleles, named HLA-B*2701 to HLA-B*2727. Studies worldwide indicate that the relatively common alleles (subtypes) HLA-B*2705, B*2704, and B*2702 are strongly associated with AS, whereas HLA-B*2706 which is prevalent in South-east Asia and HLA-B*2709 which is prevalent on the Italian island of Sardinia, seem to lack such an association. The distinction between the disease-associated subtypes and those that are not associated, may provide clues to the actual role of HLA-B27 in disease pathogenesis. B*2706 differs from B*2704 by only two residues, and B*2709 differs from B*2705 by only one residue. Moreover, both B*2706 and B*2709 bind an endogenous peptide (derived from vasoactive intestinal peptide type 1 receptor) and also an exogenous peptide (latent membrane protein 2 of Epstein-Barr virus) but in two drastically diverse conformations. These recent X-ray diffraction studies of individual peptides in the context of different HLA-B27 alleles broaden our perception of the possible pathogenetic role of this molecule in the development of AS and related spondyloarthopathies. In summary, the pathogenetic role of HLA-B27 in AS seem to be quite heterogenous, and cannot be explained by a single mechanism, and new ideas have been raised based on the aberrant immunobiologic features of HLA-B27. [source] BANK1 is a genetic risk factor for diffuse cutaneous systemic sclerosis and has additive effects with IRF5 and STAT4ARTHRITIS & RHEUMATISM, Issue 11 2009P. Dieudé Objective To determine whether the functional BANK1 variants rs3733197 and rs10516487 are associated with systemic sclerosis (SSc) in 2 European Caucasian populations and to investigate the putative gene,gene interactions between BANK1 and IRF5 as well as STAT4. Methods BANK1 single-nucleotide polymorphisms were genotyped in a total population of 2,432 individuals. The French cohort consisted of 874 SSc patients and 955 controls (previously genotyped for both IRF5 rs2004640 and STAT4 rs7574865). The German cohort consisted of 421 SSc patients and 182 controls. Results The BANK1 variants were found to be associated with diffuse cutaneous SSc (dcSSc) in both cohorts, providing an odds ratio (OR) of 0.77 for the rs10516487 T rare allele in the combined populations of dcSSc patients as compared with the combined populations of controls (95% confidence interval [95% CI] 0.64,0.93) and an OR of 0.73 (95% CI 0.61,0.87) for the rs3733197 A rare allele. BANK1 haplotype analysis found the A-T haplotype to be protective in dcSSc patients (OR 0.70 [95% CI 0.57,0.86], P = 3.39 × 10,4) and the G-C haplotype to be a risk factor (OR 1.25 [95% CI 1.06,1.47], P = 0.008). Significant differences were also observed when the limited cutaneous subset of SSc was compared with the dcSSc subset, both for the rare alleles and for the haplotypes. The BANK1, IRF5, and STAT4 risk alleles displayed a multiplicatively increased risk of dcSSc of 1.43-fold. Conclusion Our results establish BANK1 as a new SSc genetic susceptibility factor and show that BANK1, IRF5, and STAT4 act with additive effects. [source] STAT4 is a genetic risk factor for systemic sclerosis having additive effects with IRF5 on disease susceptibility and related pulmonary fibrosisARTHRITIS & RHEUMATISM, Issue 8 2009P. Dieudé Objective Systemic sclerosis (SSc) belongs to the group of connective tissue disorders (CTDs), among which are several disorders characterized by a type I interferon (IFN) signature. The recent identification of an association between IRF5 and SSc further highlights a key role for IFN. STAT4, which encodes STAT-4, contributes to IFN signaling, and its genetic variants were found to be associated with CTDs. The aim of this study was to determine whether the STAT4 rs7574865 single-nucleotide polymorphism is associated with SSc, and whether it interacts with IRF5. Methods Both the STAT4 rs7574865 and IRF5 rs2004640 polymorphisms were genotyped in 1,855 individuals of French Caucasian origin comprising a discovery set of 440 patients with SSc and 485 control subjects and a replication set of 445 patients with SSc and an additional 485 control subjects. Results STAT4 rs7574865 was shown to be associated with SSc (P = 0.001, odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.11,1.51). This association was not restricted to a particular phenotype. An additive effect of the STAT4 rs7574865 T allele and the IRF5 rs2004640 T allele was observed, resulting in a multiplicatively increased 1.28-fold risk of SSc. The OR for SSc was 2.72 (95% CI 1.86,3.99) for combinations of genotypes with ,3 risk alleles. An additive effect was also detected for fibrosing alveolitis: carriage of at least 3 risk alleles appeared to be an independent risk factor (P = 2.2 × 10,4, OR 1.97, 95% CI 1.28,3.04). Conclusion Our results establish STAT4 rs7574865 as a new SSc genetic susceptibility factor. STAT4 and IRF5 act with additive effects in terms of susceptibility to both SSc and SSc-related fibrosing alveolitis. [source] Contribution of genetic and environmental factors in the pathogenesis of Crohn's disease in a large family with multiple casesINFLAMMATORY BOWEL DISEASES, Issue 5 2007Marie Joossens MSc Abstract Background: A large family of Moroccan immigrants was investigated. In this family the father developed Crohn's disease (CD) after moving from Morocco to Belgium and successively 4 of his 8 children subsequently developed CD. There was no previous history of familial CD. Methods: The family was interviewed at their home and an elaborated questionnaire was completed. The food and sanitation characteristics of the family were investigated. Moreover, serological markers were tested in all family members, including ASCA, ASCAg, ALCA, ACCA, Omp, and ANCA, using enzyme-linked immunosorbent assay and indirect immunofluorescence. Genetic variants in CARD15, TLR4, NOD1, CARD8, and DLG5 associated with CD were tested as well. The complete medical history of all patients was reviewed. Results: There were no known genetic variants associated with CD in this family. None of the serological antibodies could discriminate between patients and unaffected family members, although the antibody titers were higher in diseased family members as compared with the healthy family members. Conclusion: The occurrence of 5 new cases of CD within 1 Moroccan family after immigration to Belgium cannot be explained by the known genetic susceptibility factors, and thus suggests a major environmental factor probably not related to sanitation in childhood. (Inflamm Bowel Dis 2007) [source] Polymorphisms in DNA repair genes XPD and XRCC1 and p53 mutations in lung carcinomas of never-smokersMOLECULAR CARCINOGENESIS, Issue 11 2006Wei-Min Gao Abstract The etiology of lung cancer in population with little or no tobacco exposure is not well understood. Individual genetic susceptibility factors have been suggested to contribute to lung cancer risk in this population. Mutations in the p53 tumor suppressor gene are implicated in the development of lung cancer as they are frequently found in lung tumors from both smokers and never-smokers. In order to determine whether genetic polymorphisms affecting DNA repair capacity modulate p53 mutations in lung tumors from never-smokers, we compared p53 mutations with genotypes of XPD 312, XPD 751, and XRCC1 399 in lung tumors from 43 lifetime never-smokers. p53 mutations were identified in 10 (23%) cases and consisted mostly of G/C to A/T transitions. No statistically significant association was found between p53 mutations and genotypes of XPD 312 or XPD 751. However, patients with the XRCC1 399 Gln allele, that results in a lower base excision repair capacity, were more likely to have p53 mutations, compared with patients the wild-type Arg allele (P,=,0.03). In addition, the p53 mutation frequency increased with an increasing number of combined genotypes associated with a lower DNA repair capacity of XPD 312, XPD 751, and XRCC1 399 (P,=,0.02). These results suggest that individuals who never smoked and had XRCC1 399 Gln allele may be at a greater risk of p53 mutations, especially if combined with the genotypes of XPD 312 and XPD 751 that may result in a lower DNA repair capacity. © 2006 Wiley-Liss, Inc. [source] Familial myeloma and monoclonal gammopathy: A report of eight African American families,AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2009Maneesh Jain Previous descriptions of familial myeloma have been mainly of Caucasian families. We report here eight African American families with familial multiple myeloma and monoclonal gammopathy identified over a 30 year period. Six patients with multiple myeloma (MM) and two with monoclonal gammopathy of unknown significance (MGUS) reported a family history of MM or had family members with MGUS found on screening. A pedigree compiled for each family included a history of other cancers. In the eight families, 21 of 58 first degree relatives had a plasma cell dyscrasia including 12 MM, eight MGUS, and one amyloidosis patient(s). The age of the MM patients ranged from 50 to 78 years (median 61 years). Four families had two members with MM, including one mother,son and three sibling pairs. Two MM families each had two additional first degree relatives with MGUS, with three generations involved in one family. Anticipation was suggested in two families with parent,child pairs with monoclonal gammopathy. The eight pedigrees had 66 members, 21 of whom had a diagnosis of cancer, including non-Hodgkin lymphoma and Hodgkin disease, or a clonal myeloproliferative disorder other than MM. Although the mode of genetic transmission and anticipation cannot be confirmed due to the small sample size, the increased number of MM and MGUS family members suggests underlying genetic susceptibility factors for plasma cell dyscrasias and possibly for other cancers in these families. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source] Variants in TNFAIP3, STAT4, and C12orf30 loci associated with multiple autoimmune diseases are also associated with juvenile idiopathic arthritisARTHRITIS & RHEUMATISM, Issue 7 2009Sampath Prahalad Objective Subtypes of juvenile idiopathic arthritis (JIA) share phenotypic features with other autoimmune disorders. We investigated several genetic variants associated with rheumatoid arthritis (RA) and other autoimmune disorders for association with JIA to test the hypothesis that clinically distinct phenotypes share common genetic susceptibility factors. Methods Cases were 445 children with JIA, and controls were 643 healthy adults. Using the TaqMan assay, subjects were genotyped for 8 single-nucleotide polymorphisms in 7 loci including rs10499194 and rs6920220 in the TNFAIP3 locus, rs6679677 in the RSBN1 locus, rs17696736 in the C12orf30 locus, rs3761847 in the TRAF1/C5 locus, rs2104286 in the IL2RA locus, rs7574865 in the STAT4 locus, and rs2542151 in the PTPN2 locus. Alleles and genotypes were analyzed for association with JIA and JIA subtypes. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Results The strongest associations with JIA risk or protection were observed for TNFAIP3 variants rs10499194 (OR 0.74 [95% CI 0.61,0.91], P < 0.004) and rs6920220 (OR 1.30 [95% CI 1.05,1.61], P = 0.015). We also observed associations between JIA and both STAT4 (OR 1.24 [95% CI 1.02,1.51], P = 0.029) and C12orf30 (OR 1.20 [95% CI 1.01,1.43], P = 0.041) variants. The PTPN2 variant rs2542151 deviated from Hardy-Weinberg equilibrium and was excluded from analyses. Variants in IL2RA, TRAF1/C5, and RSBN1 were not associated with JIA. After stratification by JIA subtype, the TNFAIP3 and C12orf30 variants were associated with oligoarticular JIA, while the STAT4 variant was associated primarily with polyarticular JIA. Conclusion We have demonstrated associations between JIA and variants in the TNFAIP3, STAT4, and C12orf30 regions that have previously shown associations with other autoimmune diseases, including RA and systemic lupus erythematosus. Our results suggest that clinically distinct autoimmune phenotypes share common genetic susceptibility factors. [source] | ||||||||||