Impact of Rare Structural Variant Events in Newly Diagnosed Multiple Myeloma

Purpose: Whole-genome sequencing (WGS) of patients with newly diagnosed multiple myeloma (NDMM) has shown recurrent structural variant (SV) involvement in distinct regions of the genome (i.e., hotspots) and causing recurrent copy-number alterations. Together with canonical immunoglobulin translocations, these SVs are recognized as "recurrent SVs." More than half of SVs were not involved in recurrent events. The significance of these "rare SVs" has not been previously examined.

Experimental design: In this study, we utilize 752 WGS and 591 RNA sequencing data from patients with NDMM to determine the role of rare SVs in myeloma pathogenesis.

Results: Ninety-four percent of patients harbored at least one rare SV event. Rare SVs showed an SV class-specific enrichment within genes and superenhancers associated with outlier gene expression. Furthermore, known myeloma driver genes recurrently impacted by point mutations were dysregulated by rare SVs.

Conclusions: Overall, we demonstrate the association of rare SVs with aberrant gene expression supporting a potential driver role in myeloma pathogenesis.