abstract: Medium-sized deletion in the BRCA1 gene: Limitations of Sanger sequencing and MLPA analyses.

Medium-sized deletion in the BRCA1 gene: Limitations of Sanger sequencing and MLPA analyses

Sanger sequencing and MLPA analyses.
Genet Mol Biol. 2012

Abstract
We describe a family with a history of breast and ovarian cancer in which MLPA analysis of the BRCA1 gene pointed to a deletion including a part of exon 11. Further characterization confirmed a loss of 374 bp in a region completely covered by conventional sequencing which had not revealed the deletion. Because this alteration was only detected serendipitously with an MLPA probe, we calculated the probabilities of detecting medium-sized deletions in large exons by methods including initial PCR amplification. This showed that a considerable fraction of medium-sized deletions are undetectable by currently used standard methods of mutation analyses. We conclude that long, widely overlapping amplicons should be used to minimize the risk of missing medium-sized deletions. Alternatively, large exons could be completely covered by narrow-spaced MLPA probes.

Characterization of four novel BRCA2 large genomic rearrangements in Spanish breast/ovarian cancer families: review of the literature, and reevaluation of the genetic mechanisms involved in their origin.

Characterization of four novel BRCA2 large genomic rearrangements in Spanish breast/ovarian cancer families: review of the literature, and reevaluation of the genetic mechanisms involved in their origin

Breast Cancer Res Treat. 2012 Mar 21;

Abstract

Large genomic rearrangements (LGRs) at the BRCA2 locus explain a non-negligible proportion of hereditary breast and ovarian cancer (HBOC) syndromes. The multiplex ligation and probe amplification (MLPA) assay has permitted in recent years to identify several families carrying LGRs at this locus, but very few such alterations have been fully characterized at the molecular level. Yet, molecular characterization is essential to identify recurrent alterations, to analyze the genetic mechanisms underlying such alterations, or to investigate potential genotype/phenotype relationships. We have used MLPA