Germline promoter hypermethylation in BRCA1 and BRCA2 genes is not present in hereditary breast cancer patients.

Abstract

Germline promoter hypermethylation of BRCA1 and BRCA2 genes is an alternative event of gene silencing that has not been widely investigated in hereditary breast and ovarian cancer (HBOC) syndrome. We analyzed germline BRCA promoter hypermethylation in HBOC patients with and without BRCA mutations and control subjects, using a recently developed BRCA methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Neither the patients tested nor the control subjects showed germline hypermethylation of the BRCA1 and BRCA2 promoter regions analyzed. Despite the results achieved at somatic levels by other researchers, these were not confirmed in our study at the germline level. Our results show the need to establish more predictive CpG sites in the BRCA promoter regions to optimize the MS-MLPA assay for the detection of germline hypermethylation as an effective pre-screening tool for whole-BRCA genetic analysis in HBOC, because we can not rule out the existence of germline promoter hypermethylation in BRCA.