BAP1

BAP1 (BRCA1-Associated Protein 1) is a tumor suppressor gene that helps cells repair DNA damage and control cell death. When a person inherits a faulty copy of BAP1, they have a much higher lifetime risk of developing mesothelioma, uveal (eye) melanoma, kidney cancer, and certain skin tumors, a pattern called BAP1 Tumor Predisposition Syndrome. BAP1 mutations can also occur only within a tumor (somatic) without being inherited.

Origin

BAP1 was identified in 1998 by Jensen and colleagues as a protein that binds the BRCA1 breast cancer protein. Its role as a mesothelioma susceptibility gene was established in 2011 by Testa, Carbone, and colleagues, who described families with multiple cases of mesothelioma carrying inherited BAP1 mutations.

Significance in Asbestos Context

For mesothelioma patients, BAP1 status matters in three ways. First, inherited BAP1 mutations help explain why some people develop mesothelioma after relatively low asbestos exposure, and may signal the need to screen blood relatives. Second, patients with BAP1-mutated mesothelioma often have a longer survival than average and may respond differently to certain treatments, including immunotherapy and emerging PARP inhibitor trials. Third, in litigation, defendants sometimes argue that an inherited BAP1 mutation, not asbestos, caused the disease; the established medical consensus is that BAP1 and asbestos work together, and asbestos exposure remains a substantial cause even when a mutation is present.

Example Sentence

After her mesothelioma diagnosis, the oncologist recommended BAP1 genetic testing because two of her relatives had also developed unusual cancers, and a positive result could affect both her treatment options and her children's future cancer screening.

Related Terms

Mesothelioma, Tumor Suppressor Gene, Germline Mutation, BAP1 Tumor Predisposition Syndrome, Genetic Susceptibility, Uveal Melanoma

Notes

• Ask your oncologist whether your tumor and a blood sample should be tested for BAP1. Tumor-only testing cannot tell you if the mutation is inherited.
• If germline (inherited) BAP1 mutation is confirmed, request a referral to a genetic counselor; first-degree relatives (parents, siblings, children) may benefit from testing and cancer surveillance including skin exams, eye exams, and abdominal imaging.
• Preserve a copy of any genetic test report in your medical and legal files; defendants in asbestos cases may request it, and your attorneys will want to address it proactively with expert testimony.
• A BAP1 mutation does not weaken a causation case. Current medical literature treats asbestos as the necessary trigger even in genetically susceptible people, but make sure your legal team retains an expert prepared to explain this.
• Patients with BAP1-mutated mesothelioma should ask about clinical trial eligibility, including immunotherapy and DNA-repair-targeted drugs, where this mutation may predict better response.