| 1. |
- Thomassen, Mads, et al.
(författare)
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A BRCA2 mutation incorrectly mapped in the original BRCA2 reference sequence, is a common West Danish founder mutation disrupting mRNA splicing
- 2011
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 128:1, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Inherited mutations in the tumor suppressor genes BRCA1 and BRCA2 predispose carriers to breast and ovarian cancer. The authors have identified a mutation in BRCA2, 7845+1G > A (c.7617+1G > A), not previously regarded as deleterious because of incorrect mapping of the splice junction in the originally published genomic reference sequence. This reference sequence is generally used in many laboratories and it maps the mutation 16 base pairs inside intron 15. However, according to the recent reference sequences the mutation is located in the consensus donor splice sequence. By reverse transcriptase analysis, loss of exon 15 in the final transcript interrupting the open reading frame was demonstrated. Furthermore, the mutation segregates with a cancer phenotype in 18 Danish families. By genetic analysis of more than 3,500 Danish breast/ovarian cancer risk families, the mutation was identified as the most common BRCA2 mutation in West Denmark, while it is rare in Central and East Denmark and not identified in South Sweden. Haplotype analysis using dense SNP arrays indicated a common founder of the mutation approximately 1,500 years ago.
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| 2. |
- Thomassen, Mads, et al.
(författare)
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BRCA1 and BRCA2 mutations in Danish families with hereditary breast and/or ovarian cancer
- 2008
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 47:4, s. 772-777
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Tidskriftsartikel (refereegranskat)abstract
- A national study of BRCA1 and BRCA2 mutations in Danish HBOC (Hereditary Breast Ovarian Cancer) families revealed a total number of 322 mutation positive families, 206 (64%) BRCA1 and 116 (36%) BRCA2 positive families from a population of 5.5 million inhabitants. Seven hundred and twenty six mutation positive individuals were identified: 402 female BRCAl carriers, 79 male BRCAl carriers, 213 female BRCA2 carriers, and 32 male BRCA2 carriers by April 2006. Most of the mutations were frame shift or nonsense mutations, while large genomic rearrangements were rare. Most mutations were only identified in one family. A few mutations were detected repeatedly. In BRCAl the most common mutations were: 2594delC in 32 families (16%), 3438G > T in 19 families (9%), 5382insC in 16 families (8%), 3829delT in 11 families (5%). In BRCA2 the most common mutations were: 6601delA in 13 families (11%), 1538del4 in 12 families (10%), 6714del4 in 10 families (9%). There was a tendency towards a higher frequency of BRCA2 mutations in West Denmark compared to East Denmark. The frequencies of specific BRCA1 and BRCA2 mutations were slightly different in the two regions. The mutations occurring in West Denmark have also been observed in other Scandinavian countries whereas the mutations occurring in East Denmark were more often reported from other European countries and the Baltic countries. The pattern of mutation distributions are comparable with observations from other Scandinavian and European studies and indicate that the Danish BRCAl and BRCA2 mutations are a mixture of Scandinavian mutations and other European mutations including two of the Ashkenazi mutations. Even though a tendency towards founder mutations was observed most mutations were only detected once. Based on these observations we recommend that the mutation screening strategy of the BRCA1 and BRCA2 genes in Danish HBOC families comprises full screening of both genes including analysis for large genomic rearrangements.
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| 3. |
- Djureinovic, Tatjana, et al.
(författare)
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The CHEK2 1100delC variant in Swedish colorectal cancer
- 2006
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 26:6C, s. 4885-4888
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The cell cycle checkpoint kinase 2 (CHEK2) 1100delC variant has recently been identified at high frequency in families with both breast and colorectal cancer, suggesting the possible role of this variant in colorectal cancer predisposition. PATIENTS AND METHODS: To evaluate the role of CHEK2 ll00delC among Swedish colorectal cancer patients, the variant frequency was determined in 174 selected familial cases, 644 unselected cases and 760 controls, as well as in l8 families used in the genome-wide linkage analysis, where weak linkage was seen for the region harboring the CHEK2 gene. RESULTS: CHEK2 l100delC was found in 1.15% of familial and in 0.93% of unselected cases, compared to 0.66% of controls, showing no significant difference between groups. One out of 45 familial cases with a family history of breast cancer was shown to be a carrier. The variant was not identified in the 18 families included in the linkage analysis. CONCLUSION: The CHEK2 1100delC was not significantly increased in Swedish colorectal cancer patients, however, in order to determine the role of the variant in colorectal cancer families with the history of breast cancer a larger sample size is needed.
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