IVNS1ABP mutation drives cellular senescence in newly identified progeroid neuropathy

We identified a new progeroid syndrome with severe neuropathy and intellectual deficits but its underlying cellular and molecular mechanism is unknown. Exome sequencing revealed a homozygous mutation in the IVNS1ABP gene, which encodes IVNS1ABP, an influenza virus non-structural protein-1 binding protein. To investigate disease mechanisms, we generated isogenic induced pluripotent stem cells (iPSCs) from patient fibroblasts and differentiated them into neural progenitor cells (NPCs). Mutant IVNS1ABP fibroblasts, iPSCs, and NPCs exhibited defective cytokinesis, increased DNA damage, and premature cellular senescence. Consistent with these findings, cerebral organoids showed early differentiation of NPCs into neurons. Molecular profiling as well as biochemical and cellular analysis revealed altered binding of mutant IVNS1ABP to actin / actin-associated proteins and dysregulated actin dynamics during cytokinesis. Taken together, we propose that mutant IVNS1ABP dysregulates actin polymerization and organization which is at least partly responsible for the cellular senescence phenotypes in this progeroid neuropathy.