{"entity":{"id":"paper-struewing-brca-founder-mutations-ashkenazi-nejm-1997","kind":"paper","name":"The risk of cancer associated with specific mutations of BRCA1 and BRCA2 among Ashkenazi Jews","aka":[],"tldr":"The 1997 study of 5,318 Ashkenazi Jewish volunteers that measured the real-world breast cancer risk of the three founder mutations carried by more than 2 percent of that population: 56 percent by age 70, lower than the 85 percent estimated from high-risk families.","summary":"Struewing, Hartge, Wacholder, Baker and colleagues collected blood from 5,318 Jewish subjects in the Washington DC area who had completed epidemiological questionnaires and identified carriers of the BRCA1 185delAG and 5382insC mutations and the BRCA2 6174delT mutation by polymerase chain reaction assays, estimating cancer risk from the cancer histories of carriers' and non-carriers' relatives. One hundred and twenty carriers were identified. By age 70 the estimated risk of breast cancer among carriers was 56 percent (95 percent confidence interval 40 to 73), of ovarian cancer 16 percent (6 to 28) and of prostate cancer 16 percent (4 to 30); breast cancer risk did not differ between BRCA1 and BRCA2 carriers, and colon cancer incidence in relatives was not raised.","asOf":"2026-09-24","links":[{"label":"N Engl J Med 1997","url":"https://doi.org/10.1056/NEJM199705153362001"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/9145676/"}],"tags":["tnbc-evidence"],"related":[],"cancers":["tnbc","ovarian","prostate","breast-cancer"],"sections":[],"technologies":[],"targets":["brca"],"drugs":[],"companies":[],"institutions":["nci"],"pathways":[],"terms":["germline-testing","gbrca-mutation"],"trials":[],"people":["mary-claire-king"],"bottlenecks":["b-hereditary-risk"],"keyPapers":[],"journals":["nejm"],"dependsOn":[],"notes":[],"journal":"New England Journal of Medicine","year":1997,"doi":"10.1056/NEJM199705153362001","pmid":"9145676","authors":"Struewing JP, Hartge P, Wacholder S, et al.","paperType":"observational","findings":["Over 2 percent of Ashkenazi Jews carry one of three founder mutations (BRCA1 185delAG, BRCA1 5382insC, BRCA2 6174delT).","Breast cancer risk by age 70: 56 percent (95 percent CI 40 to 73); ovarian 16 percent; prostate 16 percent."],"whatItMeans":"Founder mutations make population-level testing feasible because a three-variant panel finds most carriers; the BRCA1 founder variants in particular predispose to basal-like, triple-negative tumours, so ancestry shapes who gets this disease and who is eligible for PARP inhibitors.","caveats":["Risk estimated from relatives' histories, not from following carriers.","Volunteer sample from one metropolitan area."],"changedPractice":true,"participants":5318},"route":"/key-papers/paper-struewing-brca-founder-mutations-ashkenazi-nejm-1997/","neighbours":{"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"ovarian","kind":"cancer","name":"Ovarian cancer","route":"/cancers/ovarian/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"target":[{"id":"brca","kind":"target","name":"BRCA1 / BRCA2 (HRD)","route":"/targets/brca/"}],"institution":[{"id":"nci","kind":"institution","name":"National Cancer Institute (NIH)","route":"/institutions/nci/"}],"technology":[{"id":"germline-testing","kind":"technology","name":"Germline (hereditary) testing","route":"/technologies/germline-testing/"}],"term":[{"id":"gbrca-mutation","kind":"term","name":"Germline BRCA mutation (gBRCA)","route":"/terms/gbrca-mutation/"}],"person":[{"id":"mary-claire-king","kind":"person","name":"Mary-Claire King","route":"/people/mary-claire-king/"}],"bottleneck":[{"id":"b-hereditary-risk","kind":"bottleneck","name":"Inherited risk is mostly unidentified","route":"/bottlenecks/b-hereditary-risk/"}],"journal":[{"id":"nejm","kind":"journal","name":"New England Journal of Medicine","route":"/journals/nejm/"}],"paper":[{"id":"paper-gorski-brca1-founder-mutations-poland-ajhg-2000","kind":"paper","name":"Founder mutations in the BRCA1 gene in Polish families with breast-ovarian cancer","route":"/key-papers/paper-gorski-brca1-founder-mutations-poland-ajhg-2000/"}],"roadmap":[{"id":"tnbc-roadmap","kind":"roadmap","name":"Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem","route":"/roadmaps/tnbc-roadmap/"}]}}