Molecular Diagnosis of Calpainopathies: Methods Used for Detection of Mutations in CAPN3 Gene Implicated in Limb-Girdle Muscular Dystrophy Type 2A

Limb-girdle muscular dystrophy 9LGMD) type 2A (LGMD2A; MIM253600) is an autosomal recessive disorder belonging to the group of progressive MDs. LGMD2A is characterized by symmetrical atrophy of the pelvic, scapular, and trunk muscles, elevated serum creatine kinase and a necrotic-regeneration pattern on muscular biopsies (1 – 2 ). The study of these biopsies show that the integrity of the dystrophin-associated complex is preserved in these patients, because immunohistochemical staining for dystrophin, merosin, or the various sarcoglycan (SG) proteins is normal (2 ). Other than that, there are no specific diagnostic criteria, which explains why, despite having been properly described over a century ago (3 ), this field has generated much heated controversy, but this clinical entity remained difficult to recognize.