[Tubular aggregate myopathy and Stormorken syndrome].

Calcium (Ca) is an essential regulator for a large number of cellular functions in various tissues and organs, and small disturbances of Ca homeostasis can severely compromise normal physiology. Intracellular Ca balance is mainly controlled by the reticular Ca sensor STIM1 and the plasma membrane Ca channel ORAI1 through a mechanism known as store-operated Ca entry (SOCE). Gain-of-function mutations in STIM1 or ORAI1 cause excessive extracellular Ca influx, resulting in tubular aggregate myopathy (TAM) and Stormorken syndrome (STRMK). Both disorders are spectra of the same disease and involve muscle weakness, miosis, thrombocytopenia, hyposplenism, ichthyosis, dyslexia, and short stature. Here we summarize the clinical and histological characteristics of both disorders, provide an overview on the genetic causes, and recapitulate the current knowledge on the pathomechanisms leading to the multi-systemic phenotype of tubular aggregate myopathy and Stormorken syndrome.