TARDBP mutations in motoneuron disease with frontotemporal lobar degeneration.

TDP-43 (TAR-DNA binding protein) aggregates in neuronal inclusions in motoneuron disease (MND), as well as in frontotemporal lobar degeneration (FTLD) and FTLD associated with MND (FTLD-MND). Mutations in TARDBP gene, coding for TDP-43, were found in patients with pure MND. We now describe TARDBP mutations in two patients with FTLD-MND, presenting with a behavioral variant of FTLD and semantic dementia, suggesting that TDP-43 may also have a direct pathogenic role in FTLD disorders.