STIM1 and progressive muscular dystrophy: Patients with mutations in STIM1 show the following pathological skeletal muscle conditions: congenital and global muscular hypotonia showing a decrease in muscle tone and progressive muscular dystrophy by a loss-of-function mutation (E136X)20,31,32, muscular atrophy, tubular aggregate myopathy, and/or progressive muscle weakness by STIM1 missense mutations (H72Q, D84G, H109N or H109R)20,33.