LMNB1 and Dravet syndrome: Using cerebral organoids, we demonstrate that reduced cortical folding (a shared phenotype of DS and LMNB1+/− patients) can be restored by CRISPR-Cas9 reduction of DYRK1A copy number, and that neuronal DNA damage, senescence and Lamin B1 depletion in early DS organoids can be corrected by pharmacological inhibition of DYRK1A.