Greater than 50 FUS mutations have been identified that cause FUS-mediated toxicity in ALS patients.[34,39] FUS/TLS is closely associated with ALS and frontotemporal lobar degeneration.[40] The coaggregation between mutant huntingtin and FUS/TLS is mediated by a prion-like domain in the N-terminus of FUS/TLS.[40] FUS-mutated ALS with chorea develops at an early age and has a prominent history of leg and arm chorea, but the disease progresses quickly.[16] The more subtle features of FUS-gene-associated ALS with chorea remain to be explored. The gene discussed is HTT; the disease is frontotemporal dementia.