title: Genomic rearrangements of the BRCA1 gene in Chilean breast cancer families: an MLPA analysis.
abstract: Point mutations and small deletions and insertions in BRCA1 and BRCA2 genes are responsible of about 20% of hereditary breast cancer cases in Chilean population. Studies in other populations have identified the amplification and/or deletion of one or more exons in these genes as the cause of the disease. In this study the authors determined the presence of these types of alterations in BRCA1 and BRCA2, in 74 Chilean families with breast/ovarian cancer that were negative for germline mutations in these genes. Since these alterations are not detectable using the conventional PCR-based methods, the authors use MLPA (multiplex ligation-dependent probe amplification) to detect amplifications and/or deletions in BRCA1 and BRCA2 genes. The authors identified two different alterations in BRCA1: exon 10 duplication in one family and amplification of exons 3, 5, and 6 in two families. Duplication of exon 10 contains intronic adjacent sequences suggesting gene duplication. The second rearrangement consist of a 4 times amplification of a fragment containing exons 3, 5, and 6 joined together with no introns, suggesting the presence of a processed pseudogene. No alterations were detected in BRCA2. In order to validate the MLPA results and characterize the genomic alterations the authors performed qPCR, long range PCR, and sequencing.
authors.affiliation: Department of Cell and Molecular Biology, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Sanchez
authors.forename: Paola
authors.initials: P
authors.lastname: Faundez
authors.forename: Pilar
authors.initials: P
authors.lastname: Carvallo
mesh_terms: D000328:Adult; D000368:Aged; D019313:BRCA1 Protein / Q000235:genetics*; D001483:Base Sequence; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D002677:Chile / Q000453:epidemiology; D005091:Exons; D005260:Female; D050939:Gene Fusion / Q000235:genetics; D023061:Gene Order; D015321:Gene Rearrangement / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D019313:BRCA1 Protein