High frequency of germline RUNX1 mutations in patients with RUNX1-mutated AML.

RUNX1 is mutated in ∼10% of adult acute myeloid leukemia (AML). Although most RUNX1 mutations in this disease are believed to be acquired, they can also be germline. Indeed, germline RUNX1 mutations result in the well-described autosomal-dominant familial platelet disorder with predisposition to hematologic malignancies (RUNX1-FPD, FPD/AML, FPDMM); ∼44% of affected individuals progress to AML or myelodysplastic syndromes. Using the Leucegene RUNX1 AML patient group, we sought to investigate the proportion of germline vs acquired RUNX1 mutations in this cohort. Our results showed that 30% of RUNX1 mutations in our AML cohort are germline. Molecular profiling revealed higher frequencies of NRAS mutations and other mutations known to activate various signaling pathways in these patients with RUNX1 germline-mutated AML. Moreover, 2 patients (mother and son) had co-occurrence of RUNX1 and CEBPA germline mutations, with variable AML disease onset at 59 and 27 years, respectively. Together, these data suggest a higher than anticipated frequency of germline RUNX1 mutations in the Leucegene cohort and further highlight the importance of testing for RUNX1 mutations in instances in which allogeneic stem cell transplantation using a related donor is envisioned.