| 1. |
- Jakubowska, A, et al.
(författare)
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Association of PHB 1630 C andgt; T and MTHFR 677 C andgt; T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study
- 2012
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Ingår i: British Journal of Cancer. - : Cancer Research UK / Nature Publishing Group. - 0007-0920 .- 1532-1827. ; 106:12, s. 2016-2024
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or indirectly in maintaining genomic integrity. less thanbrgreater than less thanbrgreater thanMETHODS: To evaluate the potential role of genetic variants within PHB and MTHFR in breast and ovarian cancer risk, 4102 BRCA1 and 2093 BRCA2 mutation carriers, and 6211 BRCA1 and 2902 BRCA2 carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA) were genotyped for the PHB 1630 Candgt;T (rs6917) polymorphism and the MTHFR 677 Candgt;T (rs1801133) polymorphism, respectively. less thanbrgreater than less thanbrgreater thanRESULTS: There was no evidence of association between the PHB 1630 Candgt;T and MTHFR 677 Candgt;T polymorphisms with either disease for BRCA1 or BRCA2 mutation carriers when breast and ovarian cancer associations were evaluated separately. Analysis that evaluated associations for breast and ovarian cancer simultaneously showed some evidence that BRCA1 mutation carriers who had the rare homozygote genotype (TT) of the PHB 1630 Candgt;T polymorphism were at increased risk of both breast and ovarian cancer (HR 1.50, 95% CI 1.10-2.04 and HR 2.16, 95% CI 1.24-3.76, respectively). However, there was no evidence of association under a multiplicative model for the effect of each minor allele. less thanbrgreater than less thanbrgreater thanCONCLUSION: The PHB 1630TT genotype may modify breast and ovarian cancer risks in BRCA1 mutation carriers. This association need to be evaluated in larger series of BRCA1 mutation carriers.
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| 2. |
- Hakansson, Sara, et al.
(författare)
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Moderate frequency of BRCA1 and BRCA2 germ-line mutations in Scandinavian familial breast cancer
- 1997
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Ingår i: American Journal of Human Genetics. - 0002-9297. ; 60:5, s. 1068-1078
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies of high-risk breast cancer families have proposed that two major breast cancer-susceptibility genes, BRCA1 and BRCA2, may account for at least two-thirds of all hereditary breast cancer. We have screened index cases from 106 Scandinavian (mainly southern Swedish) breast cancer and breast-ovarian cancer families for germ-line mutations in all coding exons of the BRCA1 and BRCA2 genes, using the protein-truncation test, SSCP analysis, or direct sequencing. A total of 24 families exhibited 11 different BRCA1 mutations, whereas 11 different BRCA2 mutations were detected in 12 families, of which 3 contained cases of male breast cancer. One BRCA2 mutation, 4486delG, was found in two families of the present study and, in a separate study, also in breast tumors from three unrelated males with unknown family history, suggesting that at least one BRCA2 founder mutation exists in the Scandinavian population. We report 1 novel BRCA1 mutation, eight additional cases of 4 BRCA1 mutations described elsewhere, and 11 novel BRCA2 mutations (9 frameshift deletions and 2 nonsense mutations), of which all are predicted to cause premature truncation of the translated products. The relatively low frequency of BRCA1 and BRCA2 mutations in the present study could be explained by insufficient screening sensitivity to the location of mutations in uncharacterized regulatory regions, the analysis of phenocopies, or, most likely, within predisposed families, additional uncharacterized BRCA genes.
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| 3. |
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| 4. |
- Loman, N, et al.
(författare)
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Family history of breast and ovarian cancers and BRCA1 and BRCA2 mutations in a population-based series of early-onset breast cancer
- 2001
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105 .- 0027-8874. ; 93:16, s. 23-1215
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: BRCA1 and BRCA2 are the two major susceptibility genes involved in hereditary breast cancer. This study was undertaken to provide reliable population-based estimates of genetic influence and to characterize the nature and prevalence of BRCA1 and BRCA2 germline mutations in early-onset breast cancer.METHODS: In a series comprising all women diagnosed with breast cancer under the age of 41 years in southern Sweden during 1990 through 1995 (n = 262), family history of cancer was evaluated in 95% (n = 250) of the case subjects and germline mutations in BRCA1 and BRCA2 were analyzed in 89% (n = 234). All statistical tests were two-sided.RESULTS: A total of 97 case subjects had at least one first- or second-degree relative with breast or ovarian cancer; 34 (14%; 95% confidence interval [CI] = 9.6% to 18%) cases had at least two first- or second-degree relatives, 22 (8.8%; 95%CI = 5.3% to 12%) had one first-degree relative, and 41 (16%; 95% CI = 12% to 21%) had one second-degree relative with either cancer. If two females affected with breast or ovarian cancer who were related through an unaffected male were also defined as first-degree relatives, then a higher number of case subjects, 120 (48%; 95% CI = 42% to 54%), had at least one first-degree or second-degree relative with breast or ovarian cancer. Sixteen (6.8%; 95% CI = 4.0% to 11%) BRCA1 mutation carriers and five (2.1%; 95% CI = 0.70% to 4.9%) BRCA2 mutation carriers were identified. Among case subjects with one first- or more than one first- or second-degree relative with breast or ovarian cancer, BRCA mutations were more frequent (P<.001) than among the case subjects without this degree of family history. BRCA mutations were also statistically significantly more common among women with bilateral breast cancer than among women with unilateral breast cancer (P =.002). BRCA mutations were more common among younger case subjects than among older ones (P =.0027).CONCLUSIONS: Almost half (48%) of women in southern Sweden with early-onset breast cancer have some family history of breast or ovarian cancer, and 9.0% of early-onset breast cancer cases are associated with a germline mutation in BRCA1 or BRCA2. Mutation carriers were more prevalent among young women, women with at least one first- or second-degree relative with breast or ovarian cancer, and women with bilateral breast cancer.
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| 5. |
- Malander, S, et al.
(författare)
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One in 10 ovarian cancer patients carry germ line BRCA1 or BRCA2 mutations : results of a prospective study in Southern Sweden
- 2004
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 1879-0852 .- 0959-8049. ; 40:3, s. 422-428
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Tidskriftsartikel (refereegranskat)abstract
- At least 10% of all ovarian cancers are estimated to have a hereditary background. Hereditary breast-ovarian cancer (HBOC) due to mutations in the BRCA genes is a major cause of hereditary ovarian cancer, although its frequency and relationship to age and family history in unselected series of ovarian cancers is not completely known. We report here the results of a full mutational screening analysis for germ line BRCA1 and BRCA2 mutations in 161 patients with invasive epithelial ovarian carcinomas. Age at diagnosis ranged from 22 to 82 years (mean 59 years). Deleterious (frame-shift, nonsense and missense) mutations were detected in 13/161 (8%) of the patients and affected BRCA1 in 12 cases and BRCA2 in one case. Four additional missense variants (one in BRCA1 and three in BRCA2) with a possible association with an increased risk ovarian cancer were revealed, resulting in a total frequency of BRCA gene alterations of 17/161 (11%). The 13 patients with deleterious mutations had a mean age of 57 years (range 41-76 years) and only three of these patients were below 50 years of age. A family history of at least one breast cancer and/or ovarian cancer was reported in all but 1 of the patients with BRCA mutations compared with only 24% of patients without mutations. Our findings in this prospective study confirm approximately 1 in 10 patients with ovarian cancer carry a germ line BRCA gene mutation associated with HBOC, and also indicate that a large number of these patients are over 50 years of age at diagnosis.
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| 6. |
- Vallon-Christersson, J, et al.
(författare)
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Functional analysis of BRCA1 C-terminal missense mutations identified in breast and ovarian cancer families
- 2001
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 10:4, s. 60-353
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Tidskriftsartikel (refereegranskat)abstract
- Germline mutations in the breast and ovarian cancer susceptibility gene BRCA1 are responsible for the majority of cases involving hereditary breast and ovarian cancer. Whereas all truncating mutations are considered as functionally deleterious, most of the missense variants identified to date cannot be readily distinguished as either disease-associated mutations or benign polymorphisms. The C-terminal domain of BRCA1 displays an intrinsic transactivation activity, and mutations linked to disease predisposition have been shown to confer loss of such activity in yeast and mammalian cells. In an attempt to clarify the functional importance of the BRCA1 C-terminus as a transcription activator in cancer predisposition, we have characterized the effect of C-terminal germline variants identified in Scandinavian breast and ovarian cancer families. Missense variants A1669S, C1697R, R1699W, R1699Q, A1708E, S1715R and G1738E and a truncating mutation, W1837X, were characterized using yeast- and mammalian-based transcription assays. In addition, four additional missense variants (V1665M, D1692N, S1715N and D1733G) and one in-frame deletion (V1688del) were included in the study. Our findings demonstrate that transactivation activity may reflect a tumor-suppressing function of BRCA1 and further support the role of BRCA1 missense mutations in disease predisposition. We also report a discrepancy between results from yeast- and mammalian-based assays, indicating that it may not be possible to unambiguously characterize variants with the yeast assay alone. We show that transcription-based assays can aid in the characterization of deleterious mutations in the C-terminal part of BRCA1 and may form the basis of a functional assay.
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| 7. |
- Winter, C, et al.
(författare)
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Targeted sequencing of BRCA1 and BRCA2 across a large unselected breast cancer cohort suggests that one-third of mutations are somatic
- 2016
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Ingår i: Annals of Oncology. - : Elsevier BV. - 1569-8041 .- 0923-7534. ; 27:8, s. 8-1532
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A mutation found in the BRCA1 or BRCA2 gene of a breast tumor could be either germline or somatically acquired. The prevalence of somatic BRCA1/2 mutations and the ratio between somatic and germline BRCA1/2 mutations in unselected breast cancer patients are currently unclear.PATIENTS AND METHODS: Paired normal and tumor DNA was analyzed for BRCA1/2 mutations by massively parallel sequencing in an unselected cohort of 273 breast cancer patients from south Sweden.RESULTS: Deleterious germline mutations in BRCA1 (n = 10) or BRCA2 (n = 10) were detected in 20 patients (7%). Deleterious somatic mutations in BRCA1 (n = 4) or BRCA2 (n = 5) were detected in 9 patients (3%). Accordingly, about 1 in 9 breast carcinomas (11%) in our cohort harbor a BRCA1/2 mutation. For each gene, the tumor phenotypes were very similar regardless of the mutation being germline or somatically acquired, whereas the tumor phenotypes differed significantly between wild-type and mutated cases. For age at diagnosis, the patients with somatic BRCA1/2 mutations resembled the wild-type patients (median age at diagnosis, germline BRCA1: 41.5 years; germline BRCA2: 49.5 years; somatic BRCA1/2: 65 years; wild-type BRCA1/2: 62.5 years).CONCLUSIONS: In a population without strong germline founder mutations, the likelihood of a BRCA1/2 mutation found in a breast carcinoma being somatic was ∼1/3 and germline 2/3. This may have implications for treatment and genetic counseling.
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