MLH1 intronic variants mapping to + 5 position of splice donor sites lead to deleterious effects on RNA splicing.

Germline pathogenic variants in the DNA mismatch repair genes (MMR): MLH1, MSH2, MSH6, and PMS2, are causative of Lynch syndrome (LS). However, many of the variants mapping outside the invariant splice site positions (IVS ± 1, IVS ± 2) are classified as variants of unknown significance (VUS). Three such variants (MLH1 c.

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.

Germline mutations in BRCA1, BRCA2, CHEK2 and TP53 in patients at high-risk for HBOC: characterizing a Northeast Brazilian Population.

Considering the importance of BRCA1, BRCA2, CHEK2 and TP53 in the development of hereditary early-onset breast and ovarian cancer and that the genetic susceptibility profile of the Northeast population from Brazil has never been analyzed, this study aimed to verify the frequency of mutations of clinical significance in these genes in high-risk hereditary breast and ovarian cancer (HBOC) syndrome patients from that region. DNA samples from 106 high-risk unrelated patients mostly from Bahia, the biggest state in the Northeast region, were analyzed. These patients underwent full BRCA1 gene sequencing, screening for common founder mutations in the BRCA2, CHEK2 and TP53 genes and genetic ancestry analysis with nine ancestry informative markers.