Tubular aggregate myopathies (TAM) are progressive muscle disorders characterized by abnormal accumulations of densely packed membrane tubules on biopsies. The implicated gene STIM1 controls intracellular calcium balance and plays an important role in the regulation of muscle contraction. Here we describe patients with new STIM1 mutations clustering the calcium-binding domain and impairing normal protein function. Patient phenotypes ranged from childhood onset muscle weakness to adult-onset myalgia without muscle weakness, expanding the spectrum associated with this muscle disorder. Our study indicates a genotype/phenotype correlation for tubular aggregate myopathies, and has an important diagnostic relevance. (By Dr. Johann Böhm, http://jmg.bmj.com/content/early/2014/10/17/jmedgenet-2014-102623 )