Submitted by Francisco E. Gomez, MD, News Science Editorial Board
Edited by Benn E. Smith, MD, News Science Editorial Board
Diaz-Manera J, et al. Muscle MRI in patients with dysferlinopathy: Pattern recognition and implications for clinical trials
. J Neurol Neurosurg Psychiatry
Dysferlinopathies are a group of autosomal recessive diseases that occur when there is decreased or absent expression of the DYSF gene product dysferlin.
Under normal conditions, this protein is involved in membrane repair, and its absence results in muscle fiber necrosis, culminating in replacement of muscle tissue with fat and fibrosis as well as clinical weakness. Dysferlinopathies usually manifest in young adulthood with increased CK and progressive weakness that rarely affects respiratory or cardiac muscle. The most common forms are limb girdle dystrophy 2B and Miyoshi myopathy.
The authors of this research paper sought to describe the pattern and natural history of muscle involvement in said diseases via MRI studies in 185 patients with confirmed mutations. Sequences involved T1, Dixon, B1 Maps and T2, analyzed via T1 Fischer modified Mercuri visual scales.
Quite notably, they describe a characteristic pattern of muscle involvement in dysferlinopathies, independent of clinical phenotype and distinct from other entities such as Becker muscular dystrophy or sarcoglycanopathies.
Dysferlinopathies show fat replacement early on in posterior lower limb muscles (gastrocnemius and soleus) as well as posterior thigh muscles (semimembranosus, semitendinosus and adductor major), pelvic muscles (tensor fascia lata and obturator externus), paraspinals (iliocostalis, multifidus) and scapular muscles (subscapularis, latisimus dorsi) with latter involvement of other muscle groups (levator scapulae, rhomboideus, glutei and gracilis)
This study is of interest to clinicians, as certain genetic diseases may be suspected via imaging findings.