Elevated Urinary Titin in Adult Spinal Muscular Atrophy: A Multicenter, Cross-Sectional Observational Study

Background: Spinal muscular atrophy (SMA) is a treatable motor neuron disease. Biomarkers for skeletal muscle atrophy are extremely important for measuring the effects of treatment and monitoring the natural course of the disease. The urinary titin N fragment (UNT) has recently been proven to be related to muscle damage. Methods: The UNT was measured in 41 patients with SMA and 41 healthy controls. Clinical data, functional tests, and laboratory findings were also recorded. Results: We found significantly higher UNT levels in the patient samples than in the healthy subjects. The UNT was not related to disease type, functional test results, or serum creatine kinase levels. Conclusions: This cross-sectional study highlights the importance of the UNT as a potential noninvasive biomarker for spinal muscular atrophy. Its role can potentially be verified through longitudinal studies.