Definition:

Central core disease (CCD) is an inherited neuromuscular disorder characterized by central cores on muscle biopsy and clinical features of a congenital myopathy. CCD is usually inherited as an autosomal dominant trait but recessive inheritance has been recently described in few families. The clinical phenotype of dominantly inherited CCD is variable but usually mild and non-progressive; however, more severe forms including the fetal akinesia syndrome have also been reported associated with recessive or de novo dominant mutations. CCD typically presents in infancy with hypotonia and motor developmental delay and is characterized by predominantly proximal weakness pronounced in the hip girdle. CCD is due to mutations in the skeletal muscle ryanodine receptor (RYR1) gene, encoding the principal skeletal muscle sarcoplasmic reticulum calcium release channel (RyR1). Altered excitability and/or changes in calcium homeostasis within muscle cells due to mutation-induced conformational changes of the RyR protein are considered the main pathogenetic mechanisms.