SRP54 and myopathy: The present case series of 100 patients with inflammatory myopathy with anti-SRP antibody provided the following findings: (i) patients of all ages were affected; (ii) neurological symptoms were characterized by severe limb, trunk, and bulbar muscle weakness with atrophy; (iii) histological diagnoses showed 84 patients had necrotizing myopathy; (iv) anti-SRP54 antibodies were undetectable in 18 serum samples containing autoantibodies to 7S RNA of SRP; and (v) pediatric disease onset was associated with the poor neurological outcome.