RT Journal Article SR Electronic T1 Prevalence of BRCA1/2 germline mutations in 21 401 families with breast and ovarian cancer JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 465 OP 471 DO 10.1136/jmedgenet-2015-103672 VO 53 IS 7 A1 Karin Kast A1 Kerstin Rhiem A1 Barbara Wappenschmidt A1 Eric Hahnen A1 Jan Hauke A1 Britta Bluemcke A1 Verena Zarghooni A1 Natalie Herold A1 Nina Ditsch A1 Marion Kiechle A1 Michael Braun A1 Christine Fischer A1 Nicola Dikow A1 Sarah Schott A1 Nils Rahner A1 Dieter Niederacher A1 Tanja Fehm A1 Andrea Gehrig A1 Clemens Mueller-Reible A1 Norbert Arnold A1 Nicolai Maass A1 Guntram Borck A1 Nikolaus de Gregorio A1 Caroline Scholz A1 Bernd Auber A1 Raymonda Varon-Manteeva A1 Dorothee Speiser A1 Judit Horvath A1 Nadine Lichey A1 Pauline Wimberger A1 Sylvia Stark A1 Ulrike Faust A1 Bernhard H F Weber A1 Gunter Emons A1 Silke Zachariae A1 Alfons Meindl A1 Rita K Schmutzler A1 Christoph Engel YR 2016 UL http://jmg.bmj.com/content/53/7/465.abstract AB Purpose To characterise the prevalence of pathogenic germline mutations in BRCA1 and BRCA2 in families with breast cancer (BC) and ovarian cancer (OC) history.Patients and methods Data from 21 401 families were gathered between 1996 and 2014 in a clinical setting in the German Consortium for Hereditary Breast and Ovarian Cancer, comprising full pedigrees with cancer status of all individual members at the time of first counselling, and BRCA1/2 mutation status of the index patient.Results The overall BRCA1/2 mutation prevalence was 24.0% (95% CI 23.4% to 24.6%). Highest mutation frequencies were observed in families with at least two OCs (41.9%, 95% CI 36.1% to 48.0%) and families with at least one breast and one OC (41.6%, 95% CI 40.3% to 43.0%), followed by male BC with at least one female BC or OC (35.8%; 95% CI 32.2% to 39.6%). In families with a single case of early BC (<36 years), mutations were found in 13.7% (95% CI 11.9% to 15.7%). Postmenopausal unilateral or bilateral BC did not increase the probability of mutation detection. Occurrence of premenopausal BC and OC in the same woman led to higher mutation frequencies compared with the occurrence of these two cancers in different individuals (49.0%; 95% CI 41.0% to 57.0% vs 31.5%; 95% CI 28.0% to 35.2%).Conclusions Our data provide guidance for healthcare professionals and decision-makers to identify individuals who should undergo genetic testing for hereditary breast and ovarian cancer. Moreover, it supports informed decision-making of counselees on the uptake of genetic testing.