Key Points Germ line variants in TERT, SH2B3, TET2, ATM, CHEK2, PINT, and GFI1B are associated with JAK2 V617F clonal hematopoiesis and MPNs. Age-related JAK2 V617F clonal hematopoiesis is found in ∼2 out of 1000 individuals in the general population.