74 resultados para Ashkenazi
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BRCA1 and BRCA2 carriers are at increased risk for both breast and ovarian cancer, but estimates of lifetime risk vary widely, suggesting their penetrance is modified by other genetic and/or environmental factors. The BRCA1 and BRCA2 proteins function in DNA repair in conjunction with RAD51. A preliminary report suggested that a single nucleotide polymorphism in the 5′ untranslated region of RAD51 (135C/G) increases breast cancer risk in BRCA1 and BRCA2 carriers. To investigate this effect we studied 257 female Ashkenazi Jewish carriers of one of the common BRCA1 (185delAG, 5382insC) or BRCA2 (6174delT) mutations. Of this group, 164 were affected with breast and/or ovarian cancer and 93 were unaffected. RAD51 genotyping was performed on all subjects. Among BRCA1 carriers, RAD51-135C frequency was similar in healthy and affected women [6.1% (3 of 49) and 9.9% (12 of 121), respectively], and RAD-135C did not influence age of cancer diagnosis [Hazard ratio (HR) = 1.18 for disease in RAD51-135C heterozygotes, not significant]. However, in BRCA2 carriers, RAD51-135C heterozygote frequency in affected women was 17.4% (8 of 46) compared with 4.9% (2 of 41) in unaffected women (P = 0.07). Survival analysis in BRCA2 carriers showed RAD51-135C increased risk of breast and/or ovarian cancer with an HR of 4.0 [95% confidence interval 1.6–9.8, P = 0.003]. This effect was largely due to increased breast cancer risk with an HR of 3.46 (95% confidence interval 1.3–9.2, P = 0.01) for breast cancer in BRCA2 carriers who were RAD51-135C heterozygotes. RAD51 status did not affect ovarian cancer risk. These results show RAD51-135C is a clinically significant modifier of BRCA2 penetrance, specifically in raising breast cancer risk at younger ages.
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Signaling by interferon gamma (IFN-gamma) requires two structurally related cell surface proteins: a ligand-binding polypeptide, known as the IFN-gamma receptor (IFN-gamma R), and an accessory factor. However, it is not known whether IFN-gamma forms a ternary complex with the IFN-gamma R and accessory factor to initiate signaling. Here we demonstrate complex formation between IFN-gamma and the two proteins, both in solution and at the cell surface. We observe complexes containing ligand, two molecules of IFN-gamma R (designated the IFN-gamma R alpha chain), and one or two molecules of accessory factor (designated the IFN-gamma R beta chain). Transfected cells expressing both IFN-gamma R chains bind IFN-gamma with higher affinity than do cells expressing alpha chain alone. Anti-beta-chain antibodies prevent the beta chain from participating in the ligand-receptor complex, reduce the affinity for IFN-gamma, and block signaling. Soluble alpha- or beta-chain extracellular domains also inhibit function. These results demonstrate that IFN-gamma signals via a high-affinity multisubunit complex that contains two types of receptor chain and suggest a potential approach to inhibiting specific actions of IFN-gamma by blocking the association of receptor subunits.
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Mode of access: Internet.
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Mode of access: Internet.
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v. 1. Sheelot u-teshuvot, hidushim ʻal masekhet Gitin, hidushim ʻal Shulhan ʻarukh, Derushim.--v. 2. Sheelot u-teshuvot, hidushim ʻal masekhet Yebamot, derushim.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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[1] Yeḥezḳel ʻim targum Ashkenazi u-veʾur me-et Shemuʾel Deṭmold.
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Gaucher’s disease (GD) is caused by a β-glucocerebrosidase deficiency, leading to the accumulation of glucocerebroside in the reticuloendothelial system. The prevalence of GD in Tabuleiro do Norte (TN) (1:4000) is the highest in Brazil. The purpose of this study was to present evidence of consanguinity and founder effect for the G377S mutation (c.1246G>A) among GD patients in TN based on enzyme, molecular and genealogical studies. Between March 2009 and December 2010, 131 subjects at risk for GD (GC in dried blood ≤2.19 nmol/h/ml) and 5 confirmed GD patients from the same community were submitted for molecular analysis to characterize the genetic profile of the population. Based on the enzymatic and molecular analysis, the subjects were classified into three categories: affected (n=5), carrier (n=20) and non-carrier (n=111). All carriers were (G377S/wt). Affected subjects were homozygous (G377S/G377S). The identification of a single mutation in carriers and homozygotes from different generations, the history of the community and the genealogy study suggest that the high prevalence of GD in this population may be due to a combination of consanguinity and founder effect for the G377S mutation
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Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2013
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Se describe la variante homocigota c.320-2A>G de TGM1 en dos hermanas con ictiosis congénita autosómica recesiva. El clonaje de los transcritos generados por esta variante permitió identificar tres mecanismos moleculares de splicing alternativos.