Clinical Determinants of Disease Progression in Patients With Beta-Sarcoglycan Gene Mutations

Background: Limb-girdle muscular dystrophy 2E (LGMD 2E), recently renamed as autosomal recessive limb-girdle dystrophy-4 (LGMDR4), is characterized by the lack of beta-sarcoglycan, normally expressed in skeletal muscles and cardiomyocytes. We hypothesized that progressive respiratory left ventricular (LV) failure LGMDR4 could be associated with age interrelated phenomena disease's natural history. Methods: conducted a retrospective review records 26 patients LGMDR4. Our primary objective was to compare rates decline among creatine phosphokinase (CPK) values, pulmonary function test (PFT) measures, echocardiographic estimates relate them patients' age. Results: The decline/year CPK, PFTs, LV are significatively bound age, ejection fraction (EF) being strongest independent variable describing disease progression. Moreover, rate differed grouped according their genetic mutations, demonstrating possible genotype–phenotype correlation. parallel trend PFT, EF values demonstrates presence simultaneous deterioration muscular, respiratory, cardiac function. Conclusions: This study expands current knowledge regarding CPK impairment LGMDR4, optimize monitoring these patients, improve quality life, provide clinical indices capable quantifying effects any new gene or drug therapy.