LAUSR

e13118Background: Somatic BAP1 mutations are very common in MM tumors (Bueno et al. Nat Genet 2016, Bott et al. Nature Genet 2011) and germline BAP1 mutations have also been shown to segregate in numerous families with clusters of malignancies including MM (Testa et al. Nat Genet 2011). However, the prevalence of germline BAP1 alterations in an unselected population of MM patients remains unknown. Methods: Unselected patients with MM were enrolled on a prospective trial (NCT01773655) to collect germline DNA, detailed family history, exposure questionnaires, and tumor tissue if available. De-identified germline DNA sequencing was performed to evaluate for the presence of BAP1 mutations. Patients with prespecified high-risk criteria (age < 50 yrs, no asbestos exposure, personal/family history of choroidal nevus, uveal melanoma, melanoma, or mesothelioma, or cancer in ≥ two 1st degree relatives) were contacted by Clinical Genetics and offered counseling and identified BAP1 testing. Results: 120 patietns with...