GATA2 monoallelic expression underlies reduced penetrance in inherited GATA2-mutated MDS/AML.

Saudi Arabian Ministry of Higher Education through a doctoral scholarship awarded to A.F.A.S. and a Bloodwise Programme grant (14032) awarded to J.F., T.V., and I.D

The complex genetic landscape of familial MDS and AML reveals pathogenic germline variants.

The inclusion of familial myeloid malignancies as a separate disease entity in the revised WHO classification has renewed efforts to improve the recognition and management of this group of at risk individuals. Here we report a cohort of 86 acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) families with 49 harboring germline variants in 16 previously defined loci (57%). Whole exome sequencing in a further 37 uncharacterized families (43%) allowed us to rationalize 65 new candidate loci, including genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1 and SEC23B), reported in prior MDS/AML or inherited bone marrow failure series (DNAH9, NAPRT1 and SH2B3) or variants at novel loci (DHX34) that appear specific to inherited forms of myeloid malignancies. Altogether, our series of MDS/AML families offer novel insights into the etiology of myeloid malignancies and provide a framework to prioritize variants for inclusion into routine diagnostics and patient management

KDM5 inhibition offers a novel therapeutic strategy for the treatment of KMT2D mutant lymphomas

Loss-of-function mutations in KMT2D are a striking feature of the germinal centre (GC) lymphomas, resulting in decreased H3K4-methylation and altered gene expression. We hypothesised that inhibition of the KDM5 family, which demethylates H3K4me3/me2, would re-establish H3K4-methylation and restore the expression of genes repressed upon loss of KMT2D. KDM5-inhibition increased H3K4me3 levels and caused an anti-proliferative response in vitro, which was markedly greater in both endogenous and CRISPR-edited KMT2D mutant DLBCL cell lines, while tumour growth was inhibited in KMT2D mutant xenografts in vivo. KDM5-inhibition reactivated both KMT2D-dependent and -independent genes, resulting in diminished B-cell signalling and altered expression of BCL2 family members, including BCL2 itself. KDM5-inhibition may offer an effective therapeutic strategy for ameliorating KMT2D loss-of-function mutations in GC-lymphomas