In contrast, mutations in the ubiquitous reticular Ca2+ sensor STIM1 or the ubiquitous plasma membrane Ca2+ channel ORAI1 give rise to a multi-systemic phenotype involving muscle weakness in combination with a variable degree of additional signs such as miosis, ichthyosis, short stature, thrombocytopenia, and hyposplenism [7,9,10,11]. The gene discussed is STIM1; the disease is Thrombocytopenia.