The germline mutational landscape of BRCA1 and BRCA2 in Brazil

The detection of germline mutations in BRCA1 and BRCA2 is essential to the formulation of clinical management strategies, and in Brazil, there is limited access to these services, mainly due to the costs/availability of genetic testing. Aiming at the identification of recurrent mutations that could be included in a low-cost mutation panel, used as a first screening approach, we compiled the testing reports of 649 probands with pathogenic/likely pathogenic variants referred to 28 public and private health care centers distributed across 11 Brazilian States. Overall, 126 and 103 distinct mutations were identified in BRCA1 and BRCA2, respectively. Twenty-six novel variants were reported from both genes, and BRCA2 showed higher mutational heterogeneity. Some recurrent mutations were reported exclusively in certain geographic regions, suggesting a founder effect. Our findings confirm that there is significant molecular heterogeneity in these genes among Brazilian carriers, while also suggesting that this heterogeneity precludes the use of screening protocols that include recurrent mutation testing only. This is the first study to show that profiles of recurrent mutations may be unique to different Brazilian regions. These data should be explored in larger regional cohorts to determine if screening with a panel of recurrent mutations would be effective. ; This work was supported in part by grants from Barretos Cancer Hospital (FINEP - CT-INFRA, 02/2010), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, 2013/24633-2 and 2103/23277-8), Fundação de Apoio à Pesquisa do Rio Grande do Norte (FAPERN), Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), Ministério da Saúde, the Breast Cancer Research Foundation (Avon grant #02-2013-044) and National Institute of Health/National Cancer Institute (grant #RC4 CA153828-01) for the Clinical Cancer Genomics Community Research Network. Support in part was provided by grants from ...