Using the LmnaDhe mouse model, which recapitulates some physiological phenotypes of HGPS and other non-muscle involved laminopathies, we show here that the slowed cell growth caused by Lmna mutation is in part due to mitotic defects that include loss of the centromere-specific condensin subunit, NCAP-D3, and a defective spindle checkpoint. The gene discussed is LMNA; the disease is laminopathy.