DNAJB6 and myopathy: DNAJB6 mutations explain 6.4 % of our collection of genetically undefined vacuolar and myofibrillar myopathies – DNAJB6 mutations were present in 4 of 63 of our patients followed at the Besta Neurological institute with LGMD or distal phenotype, muscle histopathology characterized by vacuolation and/or myofibrillar abnormalities, and no mutations in the known genes associated with these pathologies.