Dysferlinopathies

Abstract

Primary dysferlinopathies are a group of autosomal recessive heterogeneousneuromuscular disorders and are due to mutations in the 55-exon gene, located at 2p13,and encodes the protein dysferlin. There is heterogeneity variability in the clinicalpresentations, which range from limb girdle muscular dystrophy 2B (LGMD2), Miyoshimyopathy and DMAT to isolated hyperCKemia and severe functional disability. InLGMD2B, the proximal muscles of the lower limbs are involved whereas in Miyoshimyopathy (MM) symptoms begin in the posterior muscle compartment of the calf andthey later spread to the upper muscles. In DMAT, the anterior muscle weakness is thefirst symptom to appear progressing rapidly to the lower and upper proximal muscles.The onset of MM and LGMD2B is generally in the teens or early adulthood. CK isalways very high. The morphological findings of primary dysferlinopathies show fiberssize variability, fiber splitting, necrotic and regenerative fibers. The diagnosis of thedisorder is made by the reduction or absence of dysferlin in muscles of the affectedpatients performed by immunohistochemistry and immunoblotting with dysferlinmonoclonal antibodies. The molecular analysis confirms the diagnosis. © 2013 Nova Science Publishers, Inc. All rights reserved.