BAP1 and cutaneous mastocytosis: In the majority of families with multiple cases of one type of a BAP1-TPDS-associated malignancy, no pathogenic germline aberration was found in BAP1. The reported frequencies of a pathogenic germline BAP1 variant in familial UM are 20% and 25% [24,69], in familial CM 0.7% [32], and in MMe 7.7% and 20% [33,70].