Background: Breast cancer (BC) is the most common cancer and related cause of mortality among Hispanics, yet susceptibility has been understudied. BRCA1 and BRCA2 (BRCA) mutations explain less than one-half of hereditary BC, and the proportion associated with other BC susceptibility genes is unknown.
Methods: Germline DNA from 1054 BRCA-mutation-negative Hispanic women with hereditary BC (BC diagnosed at age <51 years, bilateral BC, breast and ovarian cancer, or BC diagnosed at ages 51-70 years with ≥2 first-degree or second-degree relatives who had BC diagnosed at age <70 years), 312 local controls, and 887 multiethnic cohort controls was sequenced and analyzed for 12 known and suspected, high-penetrance and moderate-penetrance cancer susceptibility genes (ataxia telangiectasia mutated [ATM], breast cancer 1 interacting protein C-terminal helicase 1 [BRIP1], cadherin 1 [CDH1], checkpoint kinase 2 [CHEK2], nibrin [NBN], neurofibromatosis type 1 [NF1], partner and localizer of BRCA2 [PALB2], phosphatase and tensin homolog [PTEN], RAD51 paralog 3 [RAD51C], RAD51D, serine/threonine kinase 11 [STK11], and TP53).