Aberrant splicing of U12-type introns is the hallmark of ZRSR2 mutant myelodysplastic syndrome

Somatic mutations in components of the core RNA splicing machinery, including ZRSR2, have been implicated in myelodysplastic syndrome (MDS). Here, Madan et al. show that ZRSR2 plays a pivotal role in splicing of the U12-type introns, while the U2-dependent splicing is largely unaffected in ZRSR2 mutant MDS bone marrow.