Muscle-specific discordant skewing of X-chromosome inactivation leads to different clinical phenotypes of Duchenne muscular dystrophy in two monozygotic female twins

Abstract

Background: Mutations within the DMD gene leading to the absence or vast reduction of dystrophin cause Duchenne muscular dystrophy (DMD). The majority of female heterozygous carriers of X-linked recessive DMD mutations are asymptomatic or mildly affected due to the balanced X-inactivation. However, in rare cases of female DMD carriers skewed X-inactivation leads to clinical symptoms.