Dystrophinopathies

Abstract

Dystrophinopathies are a group of genetic disorders mainly affecting skeletal andcardiac muscle, caused by deficiency of the protein dystrophin at the sarcolemma ofmuscle fibers. Dystrophin is encoded by the Duchenne muscular dystrophy gene (DMD),linked to the Xp21 locus. Duchenne muscular dystrophy (DMD) is the severe form ofdystrophinopathy caused by a complete deficiency of dystrophin protein, affecting 1 in ~4,000 newborn males and representing one of the most common lethal childhooddisorders. Becker muscular dystrophy (BMD) is the relatively milder condition caused bythe presence of a reduced and/or partially functional dystrophin protein, and its clinicalmanifestations range from severe to mild. Disease manifestations are relatively rare inDMD/BMD carriers. Dilated cardiomyopathy (DCM) and respiratory insufficiency arethe most frequent complications of dystrophinopathies. Mental retardation is found in asmall percentage of patients. To date, dystrophinopathies have no definitive cure, butbenefit from palliative pharmacological therapy with steroids, and multidisciplinary carefor prevention and management of complications. Experimental molecular and genetictherapies are under development but their efficacy has yet to be proven. © 2013 Nova Science Publishers, Inc. All rights reserved.