Reader Response: Prospective Natural History Study in 24 Adult Patients With LGMDR12 Over 2 Years of Follow-up: Quantitative MRI and Clinical Outcome Measures

Summary: Limb-girdle muscular dystrophy R12 (LGMD-R12) is mainly found in males, and female patients are less likely to have severe muscle and/or cardiac pathology. A mouse model of LGMD-R12 showed similar sex differences as observed in humans. Male Ano5-/- mice had elevated serum creatine kinase and defective membrane repair after laser injury, while female Ano5-/- mice were similar to wild type. Both male and female Ano5-/- mice exhibited exercise intolerance, but echocardiography revealed that female mice had features of cardiomyopathy. This suggests a potential link between ANO5 mutations and cardiac disease in humans.

Summary: The study evaluated MRI and clinical outcome measures in patients with LGMDR12, finding that thigh muscle PDFF imaging is a sensitive measure for tracking muscle fat replacement, while Biodex isometric dynamometry can reliably capture muscle strength loss.