P.P.6 05 CAPN3 mutations in patients with idiopathic eosinophilic myositis

Eosinophilic myositis (EM) constitutes a rare pathological entity characterized by eosinophilic infiltration of skeletal muscles, usually associated with parasite infections, systemic disorders, or the intake of drugs or l-tryptophan. The exclusion of such causes defines the spectrum of idiopathic EM. Based on a protein analysis, we identified the gene encoding calpain-3, CAPN3, as a candidate for a subset of idiopathic EM. We screened CAPN3 for mutations using DHPLC and direct sequencing, in six unrelated patients, recruited on the basis of EM diagnosed after histological examination of muscle biopsy samples, without any identified aetiological factor.