ATM and hematopoietic and lymphoid system neoplasm: Although some of these variants are ancestry specific, they share molecular drivers, for example with rare variants of large effects driving cis association of mCAs spanning MPL and ATM. An association between a germline variant with presence of mCAs may lend support for classification of a variant as pathogenic in patients with blood cancer, particularly in populations that are underrepresented in genetic variant databases.