P.56 Urine titin as a novel biomarker for Duchenne muscular dystrophy

•Mdx mice lacking dystrophin have elevated urine titin levels.•Treatment with an exon skipping method rescued dystrophin expression and decreased urine titin in mdx mice.•Urine titin is elevated in patients with DMD relative to healthy subjects.•Elevated urine titin is a characteristic of DMD patients and the mdx mouse model.•Urine titin may serve as a pharmacodynamic marker for dystrophin restoration therapy.