Haplotypic characterization of BRCA1 c.5266dupC, the prevailing mutation in Brazilian hereditary breast/ovarian cancer

Abstract

Specific pathogenic mutations associated with breast cancer development can vary between ethnical groups. One example is BRCA1 c.5266dupC that was first described as a founder mutation in the Ashkenazi Jewish population,

but was later also found in other populations. In Brazil, this mutation corresponds to 20% of pathogenic BRCA1 vari- ants reported. Our objective was to investigate the haplotype component of a group of Brazilian families who inher- ited c.5266dupC in the BRCA1 gene and to verify the ancestry contribution from European, African, and Amerindian

origins. Fourteen probands carrying c.5266dupC and 16 relatives (carriers and non-carriers) were investigated. The same haplotype was observed segregating within all the families analyzed, revealing no recombinants in a region of 0.68 Mb. Ancestry analysis demonstrated that the European component was predominant among probands. The BRCA1 c.5266dupC analysis indicates that there was a founder effect in the Brazilian population.