We aimed to investigate the validity of urinary N-terminal titin (TTN) fragment as a biomarker for limb-girdle muscular dystrophy LGMDR1-calpain 3 related. Thirteen LGMDR1 patients and eleven healthy controls were enrolled for the study. LGMDR1 patients had significantly increased urinary N-terminal titin fragment concentrations than age-matched controls. Even if urinary level of titin decreased with aging, it was still high in wheelchair bound patients. Thus, our findings indicate that urinary N-terminal titin fragment is a non-invasive measure of muscle damage in LGMDR1, which could be used in disease monitoring in clinical trials even in wheelchair-bound patients.
Keywords: LGMDR1; biomarker; calpain 3; clinical trial; phenotype severity.