Evolution of the Functional and Muscular State and Quality of Life of Patients With Limb-girdle Muscular Dystrophy 2A: CALNATHIS Prospective Cohort Study

Intro:

Limb girdle muscular dystrophies were originally defined as a postnatal progressive muscle disease, which begins and primarily affects the pelvic and scapular muscles.

To be considered a form of limb-girdle muscular dystrophy, according to the European Neuromuscular Center, the condition must be described in at least two unrelated families with affected individuals achieving independent walking, must have elevated serum creatine kinase activity, must demonstrate degenerative changes on muscle imagery over the course of the disease, and must exhibit dystrophic changes on muscle histology, ultimately leading to end-stage pathology for the most affected muscles.

They are classified into dominant forms (LGMD 1, old nomenclature; LGMD D, new nomenclature) and recessive forms (LGMD 2, old nomenclature; LGMD R new nomenclature). Recessive forms predominate in terms of number of subtypes and individual prevalence, with regional variations due to founder effects in some cases (Murphy et al, 2015).

Individually, distinct subtypes of LGMD are relatively rare; however, as a group, the minimum prevalence of LGMD is probably between 2.27 per 100,000 and 10 per 100,000. In Europe and the United States, calpainopathies, also called LGMD R1 or LGMD-2A (OMIM 253600 ), are the most common of the different types of LGMD, accounting for up to 30% of all cases of recessive LGMD.