Molecular-pathologic and genetic diagnostics of limb girdle muscular dystrophy LGMD2A: presentation of first cases diagnosed in the Czech Republic
Abstract
Limb girdle muscular dystrophies (LGMD) represent a clinically and genetically heterogeneous group of progressive muscular dystrophies. Calpainopathy (LGMD2A), the most prevalent type of autosomal recessive limb girdle dystrophies, is caused by mutations in the gene that encodes skeletal muscle specific proteolytic enzyme calpain-3.
In this study, the authors present seven cases of LGMD2A. Mutational analysis of calpain-3 gene was performed in suspected cases based on the results of clinical and/or histopathologic examination.
Eight different mutations in calpain-3 gene were identified. Secondary deficiency of dysferlin expression was revealed in four patients.
Secondary dysferlin deficiencies in primary calpainopathies have not been demonstrated yet and seem to represent unknown and undescribed functional interactions between these proteins.