TARDBP and familial amyotrophic lateral sclerosis: The TARDBP gene, which encodes TDP-43, accounts for ∼4% of familial amyotrophic lateral sclerosis, 1.5% of sporadic amyotrophic lateral sclerosis patients and ∼2% of behavioural-variant frontotemporal dementia patients.20,21 Pathologically, TDP-43 pathology is present in ∼50% of frontotemporal dementia cases and 95% of amyotrophic lateral sclerosis.17 TDP-43 is an RNA/DNA-binding protein that is widely expressed, particularly in the CNS.