Prognostic tumor sequencing panels frequently identify germ line variants associated with hereditary hematopoietic malignancies

Next-generation sequencing (NGS)–based targeted gene capture panels are used to profile hematopoietic malignancies to guide prognostication and treatment decisions. Because these panels include genes associated with hereditary hematopoietic malignancies (HHMs), we hypothesized that these panels could identify pathogenic germ line variants in malignant cells, thereby identifying patients at risk for HHMs. In total, pathogenic or likely pathogenic variants in ANKRD26 , CEBPA , DDX41 , ETV6 , GATA2 , RUNX1 , or TP53 were identified in 74 (21%) of 360 patients. Germ line tissue was available for 24 patients with 25 pathogenic or likely pathogenic variants with variant allele frequencies >0.4. Six (24%) of these 25 variants were of germ line origin. Three DDX41 variants, 2 GATA2 variants, and a TP53 variant previously implicated in Li-Fraumeni syndrome were of germ line origin. No likely pathogenic/pathogenic germ line variants possessed variant allele frequencies DDX41 and GATA2 are especially likely to be of germ line origin. Thus, tumor-based panels may augment, but should not replace, comprehensive germ line–based testing and counseling.