We report here a new pathogenic germline variant in BAP1: c.783 + 2 T > C. The prevalence of pathogenic germline variants in BAP1 was 7.7% among patients with familial MPM (3/39).
Taking into account previous similar screenings, the prevalence of germline BAP1 mutations in sporadic MPM patients can be estimated around 1-2%, suggesting a minor role of germline BAP1 mutation in the pathogenesis of sporadic MPM.
We examined the expression of the 9p21.3-related proteins (p14, p15, p16, and methylthioadenosine phosphorylase (MTAP)) and BAP1 using IHC in 51 MPM and 25 RMH cases, and assessed their correlation with HD of p16 detected by FISH.
CCDC6 (coiled-coil domain containing 6) is a player of the HR response to DNA damage and has been predicted to interact with BAP1, another HR-DNA repair gene highly mutated in Malignant Pleural Mesothelioma (MPM), an aggressive cancer with poor prognosis.
Expression of BAP1 isoforms was detected by quantitative polymerase chain reaction in MPM and normal mesothelium cell lines and tumor and nontumor samples.
BAP1 and <i>p16</i> showed a specificity of 100% in discerning malignant from benign lesions because they are exclusively unexpressed or deleted in MPM.