Stormorken Syndrome Caused by STIM1 H109R Mutation

Stormorken Syndrome is an extremely rare disease with autosomal dominant inheritance, has a variable degree of multisystemic signs, including muscle weakness, miosis, thrombocytopenia, hyposplenism, ichthyosis, short stature, and dyslexia. we identified the c.326A>G mutation in a STIM1 allele (p.H109R) only in the child and not in the unaffected parents. The mutation was predicted to be harmful by protein function prediction software. We found mutations associated with TAM/STRMK upon consulting HGMD database. The variant located in the EF-hand supposedly led to constitutive STIM1 unfolding and oligomerization. The affected amino acids in this residue was evolutionarily conserved, which indicated an important functional role. The 3D structures of STIM1 and mutated proteins were constructed in SWISS-MODEL. No differences in STIM1 expression levels were observed between our case and healthy controls.