Genomic rearrangements account for more than one-third of the BRCA1 mutations.

2003 JUL 3 - (NewsRx.com & NewsRx.net) -- Genomic rearrangements account for more than one-third of the BRCA1 mutations.

According to recent research from Italy, "The recent identification of major genomic rearrangements in breast and breast/ovarian cancer families has widened the mutational spectrum of the BRCA1 gene, thus increasing the number of informative patients who can benefit from molecular screening.

"Numerous types of alterations have been identified. In different populations with variable frequencies, probably due to both ethnic diversity and the technical approach employed," wrote M. Montagna and colleagues, Azienda Ospedaliera.

"In fact, although several methods have been successfully used to detect large genomic deletions and insertions, most are laborious, time-consuming, and of variable sensitivity. In order to estimate the contribution of BRCA1 genomic rearrangements to breast/ovarian cancer predisposition in Italian families, we applied, for the first time as a diagnostic tool, the recently described multiplex ligation-dependent probe amplification (MLPA) methodology," the researchers stated.

"Among the 37 hereditary breast/ovarian cancer (HBOC) families selected, all had a high prior probability of BRCA1 mutation, and 15 were previously shown to carry a mutation in either the BRCA2 (five families) or BRCA1 gene (10 families, including one genomic rearrangement)," the researchers wrote.