Analysis of spinal magnetic resonance imaging (MRI) data from mice and 20 humans suggests that fatty infiltration of spinal muscle is a previously undetected early hallmark of a rare type of limb-girdle muscular dystrophy (LGMD). The new study, led by researchers at Children’s National Research Institute, uncovers a targetable fat-forming cellular pathway that may lead to the first treatment for a muscle disease with no approved therapy.
LGMD2B/R2, also known as dysferlinopathy, is a genetic disorder caused by mutations in the gene encoding the dysferlin protein and mainly affects limb and girdle muscles. Dysferlinopathy involves chronic inflammation and the replacement of healthy muscle fibers with fatty, fibrotic tissue as muscle is damaged.
Doctors diagnose the disease based on muscle weakness, high creatine kinase (CK) levels that indicate muscle damage, the absence of dysferlin protein in skeletal muscle or blood cells, and genetic testing. A muscle MRI is often part of the diagnostic strategy and shows elevated fat infiltration in limb and girdle muscles from affected patients, but the causal relationship between disease progression and fatty replacement of muscle is uncertai...