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Germline Variants (germline + variants)
Selected AbstractsHistopathological features of breast cancer in carriers of ATM gene variantsHISTOPATHOLOGY, Issue 5 2006R L Balleine Aims:, Germline variants in the ataxia telangiectasia mutated (ATM) gene have been implicated in increased breast cancer risk. The aim of this study was to determine whether the histopathology of breast cancers occurring in ATM variant carriers is distinctive or resembles the described BRCA1 mutation-associated phenotype. Methods:, The histopathological features of breast cancers occurring in ATM variant carriers from multiple-case breast cancer families were compared with matched controls. The test group included 21 cases of in situ and/or invasive cancer from carriers of either the IVS10-6T,G, 2424V,G or 1420L,F ATM variants in the absence of BRCA1 or BRCA2 mutations. An additional four invasive cancers from carriers of a pathogenic BRCA1 mutation in the context of a familial ATM variant were also examined. Results:, The histopathology of breast cancers in ATM variant-only carriers was not significantly different from controls and known features of BRCA1 mutation-associated cancer were rarely seen. In contrast, these features were prominent in the small group of cases with a pathogenic BRCA1 mutation. Conclusions:, Breast cancer occurring in carriers of ATM variants is not associated with distinctive histopathological features and does not resemble the tumour phenotype commonly observed in BRCA1 mutation carriers. [source] Radiation Response Genotype and Risk of Differentiated Thyroid Cancer: A Case-Control Analysis,THE LARYNGOSCOPE, Issue 6 2005Erich M. Sturgis MD Abstract Background: Radiation is the only clear etiologic agent for differentiated thyroid cancer (DTC). Understanding the factors affecting sensitivity to gamma radiation and susceptibility to DTC will be critical to early detection and prevention of DTC. Hypothesis: Germline variants of double-strand break repair genes are markers of DTC risk. Objective: Determine the frequency of common single nucleotide polymorphisms of genes of the double-strand break repair pathway in patients with DTC and cancer-free controls. Study Design: Case-control study. Methods: This study included 134 patients with DTC, 79 patients with benign thyroid lesions, and 166 cancer-free control subjects. To avoid ethnic confounding, all subjects were non-Hispanic whites. Genotype analyses were performed on DNA isolated from peripheral blood lymphocytes. Multivariate logistic regression analyses were performed to estimate the risk of DTC associated with each variant genotype. Results: The XRCC3 18067T polymorphic allele was found significantly more commonly among the DTC cases than for the control subjects (P = .006). After multivariate adjustment, having the XRCC3 18067T allele was associated with an increased risk of DTC (adjusted odds ratio [OR] = 2.1; 95% confidence interval [CI] = 1.3 to 3.4; P = .004). In addition, there was a suggestion that the XRCC3 18067T polymorphic allele was more common among the patients with benign thyroid disease (P = .054), and the homozygous polymorphic genotype was associated with risk for benign thyroid disease (adjusted OR = 2.1; 95% CI = 0.9,4.9; P = .078). Conclusions: In this case-control analysis, the XRCC3 18067T polymorphism is associated with DTC risk. However, such work needs confirmation in larger studies. [source] Mutations of APC and MYH in unrelated Italian patients with adenomatous polyposis coli,,HUMAN MUTATION, Issue 4 2005Gitana Aceto Abstract The analysis of APC and MYH mutations in adenomatous polyposis coli patients should provide clues about the genetic heterogeneity of the syndrome in human populations. The entire coding region and intron-exon borders of the APC and MYH genes were analyzed in 60 unrelated Italian adenomatous polyposis coli patients. APC analysis revealed 26 point mutations leading to premature termination, one missense variant and one deletion spanning the entire coding region in 32 unrelated patients. Novel truncating point mutations included c.1176_1177insT (p.His393_PhefsX396), c.1354_1355del (p.Val452_SerfsX458), c.2684C>A (p.Ser895X), c.2711_2712del (p.Arg904_LysfsX910), c.2758_2759del (p.Asp920_CysfsX922), c.4192_4193del (p.Ser1398_SerfsX1407), c.4717G>T (p.Glu1573X) and a novel cryptic APC exon 6 splice site. MYH analysis revealed nine different germline variants in nine patients, of whom five were homozygotes or compound heterozygotes. The mutations included 4 novel MYH missense variants (c.692G>A, p.Arg231His; c.778C>T, p.Arg260Trp; c.1121T>C, p.Leu374Pro; and c.1234C>T, p.Arg412Cys) affecting conserved amino acid residues in the ENDO3c or NUDIX domains of the protein and one novel synonymous change (c.672C>T, p.Asn224Asn). Genotype-phenotype correlations were found in carriers of APC mutations but not in carriers of biallelic MYH mutations, except for a negative correlation with low number of polyps. A distinctive characteristic of patients negative for APC and MYH mutations was a significantly (p<0.0001) older age at diagnosis compared to patients with APC mutations. Moreover, the proportion of cases with an attenuated polyposis phenotype was higher (p = 0.0008) among patients negative for APC and MYH mutations than among carriers of APC or biallelic MYH mutations. © 2005 Wiley-Liss, Inc. [source] Genetic variants in germline TP53 and MDM2 SNP309 are not associated with early onset colorectal cancer,JOURNAL OF SURGICAL ONCOLOGY, Issue 7 2008Sajid A. Khan MD Abstract Background and Objectives Colorectal cancer (CRC) arising in patients under age 30 is a rare disease, and few cases have been reported within Li-Fraumeni kindreds. To determine how often alterations in the p53 pathway genes contribute to disease susceptibility, we have evaluated patients with early onset CRC for the presence of germline variants in the p53 gene and MDM2 SNP309. Methods Thirty-five patients with CRC diagnosed before age 30 were included in this study-based on tissue availability. DNA samples from peripheral blood leukocytes were analyzed for constitutional mutations and polymorphisms in p53 as well as polymorphisms in MDM2 SNP309. Results No mutations were found in exons 4,10 of the p53 gene. The frequencies of polymorphisms in p53 and in MDM2 SNP309 did not differ from rates previously reported for normal control populations, and no polymorphism in either gene could be associated with early onset CRC. Conclusions Neither germline variants in p53 nor MDM2 SNP309 play an underlying role in the development of very early onset CRC. For the large majority of cases, the genetic basis of this disease remains unknown. J. Surg. Oncol. 2008;97:621,625. © 2008 Wiley-Liss, Inc. [source] | ||||||||||