| 1. |
- 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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| 2. |
- Sun, X F, et al.
(författare)
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A novel p53 germline alteration identified in a late onset breast cancer kindred
- 1996
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Ingår i: Oncogene. - 0950-9232. ; 13:2, s. 11-407
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Tidskriftsartikel (refereegranskat)abstract
- Germline mutations in the p53 tumor suppressor gene are associated with the Li-Fraumeni syndrome, characterized by childhood sarcoma, leukemia and early onset breast cancer and has occasionally been found also in familial breast-ovarian cancer. Most mutations found are of missense type and located in the central region of the gene (exons 5 to 8). In the present study, a germline p53 alteration was identified in a late onset breast cancer family (kindred Lund 5; mean age 58 years) using single stranded conformation polymorphism and sequence analysis. The mutation (a CCG to CTG transition) at codon 82 in exon 4, resulting in a proline to leucine substitution, has not previously been reported and was not present in a control set of 60 healthy individuals. Three of five woman with breast cancer (45, 57 and 65 years) were carriers of the alteration. Loss of heterozygosity at the p53 locus was not seen in the primary tumors of these women, but appeared as a partial loss of the wildtype allele in subsequent recurrent lesions of two gene carriers. The family manifested no linkage to the p53 gene (a two-point LOD-score of -0.41), and has previously also been excluded for linkage to the BRCA1 and BRCA2 loci, as well as being carrier of a BRCA1 germline mutation. Although it seems unlikely that the p53 germline mutation is the major cause of disease predisposition in Lund 5, the data suggest that some p53 alteration may confer a subtle influence on breast cancer development and progression.
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