Clin Genet 2014 Printed in Singapore. All rights reserved © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd CLINICAL GENETICS doi: 10.1111/cge.12524 Short Report Mutations predisposing to breast cancer in 12 candidate genes in breast cancer patients from Poland Cybulski C., Lubi´ nski J., Wokołorczyk D., Ku´ zniak W., Kashyap A., Sopik V., Huzarski T., Gronwald J., Byrski T., Szwiec M., Jakubowska A., Górski B., D ¸ ebniak T., Narod S.A., Akbari M.R. Mutations predisposing to breast cancer in 12 candidate genes in breast cancer patients from Poland. Clin Genet 2014. © John Wiley & Sons A/S. Published by John Wiley & Sons Ltd, 2014 A number of genes other than BRCA1 and BRCA2 have been associated with breast cancer predisposition, and extended genetic testing panels have been proposed. It is of interest to establish the full spectrum of deleterious mutations in women with familial breast cancer.We performed whole-exome sequencing of 144 women with familial breast cancer and negative for 11 Polish founder mutations in BRCA1, CHEK2 and NBS1, and we evaluated the sequences of 12 known breast cancer susceptibility genes. A truncating mutation in a breast cancer gene was detected in 24 of 144 women (17%) with familial breast cancer. A BRCA2 mutation was detected in 12 cases, a (non-founder) BRCA1 mutation was detected in 5 cases, a PALB2 mutation was detected in 4 cases and an ATM mutation was detected in 2 cases. Polish women with familial breast cancer who are negative for founder mutations in BRCA1, CHEK2 and NBS1 should be fully screened for mutations in BRCA1, BRCA2 and PALB2. The PALB2 founder mutation c.509_519delGA should be included in the panel of Polish founder mutations. Conflict of interest The authors declare that they have no competing interests. C. Cybulski a , J. Lubi ´ nski a , D. Wokolorczyk a , W. Ku´ zniak a , A. Kashyap a , V. Sopik b , T. Huzarski a , J. Gronwald a , T. Byrski a , M. Szwiec c , A. Jakubowska a , B. Górski a , T. D ¸ ebniak a , S.A Narod b,d and M.R Akbari b,d a Department of Genetics and Pathology, International Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland, b Women’s College Research Institute, Women’s College Hospital, University of Toronto, Toronto, Canada, c Tadeusz Koszarowski Regional Oncology Center, Opole, Poland, and d Dalla Lana School of Public Health, University of Toronto, Toronto, Canada Key words: ATM – BRCA1 – BRCA2 – breast cancer – BRIP – CHEK2 – hereditary – mutation – PALB2 – whole-exome sequencing Corresponding authors: Mohammad Akbari, Women’s College Research Institute, 790 Bay Street, Toronto, Ontario, Canada, M5G 1N8. Tel: +1 416 351 3765 Fax: +1 416 351 3767 e-mail: mohammad.akbari@utoronto.ca Steven Narod, Women’s College Research Institute, 790 Bay Street, 7th Floor, Toronto, Ontario, Canada, M5G 1 N8. Tel.: +1 416 351 3765; fax: +1 416 351 3767; e-mail: Steven.narod@wchospital.ca Received 14 August 2014, revised and accepted for publication 10 October 2014 Genetic testing is widely available throughout North America and Europe for two breast cancer suscepti- bility genes, BRCA1 and BRCA2. Other breast cancer genes include p53, PTEN, CDH1 and PALB2, however mutations in these are rare (1–3). Cancer suscepti- bility genes with lower penetrance include CHEK2, ATM, BARD1, BLM, BRIP1, XRCC2 and NBS1 (4–10). Recently, expanded genetic testing of a wide panel of 1