Background: The frequency and the type of BRCA1 mutations vary widely and might have different geographic and ethnic distribution. Most of these alterations are generally found in isolated populations as a consequence of the founder effect. The object of this study was to determine whether 4843delC, a deleterious mutation of the BRCA1 gene, might be due to a founder effect originating in the Sicilian region of Italy. This mutation was described by us for the first time and identified in two unrelated Sicilian families with hereditary breast/ovarian cancer. The two families were from the same geographical area (south-western area of Palermo, Sicily). The homogeneity of the ethnic group of the two families and the Single Nucleotide Polymorphism (SNPs) analysis of probands led us to perform a study of the allelotype of the various members.
Patients and methods: The analysis of the haplotype of the probands and of several family members was conducted by means of a study of the highly polymorphic microsatellites within or flanking the BRCA1 gene.
Results: This analysis revealed the presence of a common allele associated with the mutation.
Conclusions: We therefore conclude that 4843delC of the BRCA1 gene is a possible founder mutation in the Sicilian population.