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Opportunistic testing of BRCA1 , BRCA2 and mismatch repair genes improves the yield of phenotype driven hereditary cancer gene panels
Author(s) -
Feliubadaló Lídia,
LópezFernández Adrià,
Pineda Marta,
Díez Orland,
Valle Jesús,
GutiérrezEnríquez Sara,
Teulé Alex,
González Sara,
Stjepanovic Neda,
Salinas Mónica,
Capellá Gabriel,
Brunet Joan,
Lázaro Conxi,
Balmaña Judith
Publication year - 2019
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.32304
Subject(s) - msh6 , chek2 , genetic testing , medicine , germline mutation , dna mismatch repair , colorectal cancer , proband , lynch syndrome , cancer , phenotype , li–fraumeni syndrome , genetics , oncology , germline , genetic counseling , mutation , gene , biology
Multigene panels provide a powerful tool for analyzing several genes simultaneously. We evaluated the frequency of pathogenic variants (PV) in customized predefined panels according to clinical suspicion by phenotype and compared it to the yield obtained in the analysis of our clinical research gene panel. We also investigated mutational yield of opportunistic testing of BRCA1/2 and mismatch repair (MMR) genes in all patients. A total of 1,205 unrelated probands with clinical suspicion of hereditary cancer were screened for germline mutations using panel testing. Overall, 1,048 females and 157 males were analyzed, mean age at cancer diagnosis was 48; 883 had hereditary breast/ovarian cancer‐suspicion, 205 hereditary nonpolyposis colorectal cancer (HNPCC)‐suspicion, 73 adenomatous‐polyposis‐suspicion and 44 with other/multiple clinical criteria. At least one PV was found in 150 probands (12%) analyzed by our customized phenotype‐driven panel. Tumoral MMR deficiency predicted for the presence of germline MMR gene mutations in patients with HNPCC‐suspicion (46/136 vs . 0/56 in patients with and without MMR deficiency, respectively). Opportunistic testing additionally identified five MSH6 , one BRCA1 and one BRCA2 carriers (0.6%). The analysis of the extended 24‐gene panel provided 25 additional PVs (2%), including in 4 out of 51 individuals harboring MMR‐proficient colorectal tumors (2 CHEK2 and 2 ATM ). Phenotype‐based panels provide a notable rate of PVs with clinical actionability. Opportunistic testing of MMR and BRCA genes leads to a significant straightforward identification of MSH6 , BRCA1 and BRCA2 mutation carriers, and endorses the model of opportunistic testing of genes with clinical utility within a standard genetic counseling framework.