Since SMN as well as TDP-43 and FUS are known to be mutated in defined diseases of the muscular-skeletal system such as ALS and/or in cortical degenerative disorders leading to FTD, an aberrant function of these proteins at (pre-)synaptic sites has to be taken into consideration with respect to a common pathophysiological mechanism. The gene discussed is TARDBP; the disease is frontotemporal dementia.