Motor neuron control of skeletal muscle is affected in a wide range of inherited and acquired neuromuscular diseases with severe impact on mobility and life expectancy. In amyotrophic lateral sclerosis (ALS), for example, the rapid deterioration of motor neurons leads on average to death in 3-5 years due to respiratory failure. There is also a growing awareness that peripheral nervous system dysfunction, including motor neuron loss, during aging could contribute to mobility disability in frailty and sarcopenia. With declining mobility in the elderly associated with a high incidence of other debilitating diseases such as diabetes, cardiovascular problems and even declining cognitive function, it is clear that maintaining motor control will be key to sustaining a healthy aging population. Within the peripheral nerve group of the Musculoskeletal Disease Area (MSD) we have focused our research efforts around iPS-technology and patient-derived cells in collaboration with colleagues from the Chemical Biology & Therapeutics department. Using genetically-defined diseases as a starting point, we are establishing in vitro model systems of motor neuron and neuromuscular pathophysiology that we hope could ultimately have application for age-related dysfunction.