Central Core Disease - A Disease That Is Easily Misdiagnosed as Duchenne Muscular Dystrophy

Abstract

As a kind of congenital myopathy (CM), central core disease (CCD) is mainly characterized by low muscle tension, slow progressive or static proximal limb weakness. CM can be characterized by no symptoms to be unable to walk independently in the clinic, pathological changes can be manifested as only significant type 1 muscle fiber dominant type to typical central axial space structure, and there are also many genetic ways. Duchenne muscular dystrophy (DMD) is a common congenital myopathy, which is mainly manifested in the typical pathological changes of early progressive myasthenia and muscular dystrophy. Both CCD and DMD show similar clinical symptoms and their serum creatine kinase can be increased, which is often difficult to distinguish them through clinical characterization and laboratory examination. In this study, we report the clinical and genetic characteristics of two patients with progressive muscle weakness with elevated creatine kinase. They are the product of a first-cousin marriage and seek medical treatment due to asymptotic walking difficulties, muscle atrophy, joint contracture, scoliosis, and elevated creatine kinase levels. It was previously suspected as Duchenne muscular dystrophy. After that, the patient's DNA was sequenced by whole-exome sequencing (WES), and all coding regions were investigated. It was found that a new heterozygous missense mutation c.5092g > A in the RYR1 gene. Similar mutations have not been reported in the literature before. Bioinformatics software predicts that they have the possibility of pathogenesis, which is highly correlated with CCD. The purpose of this case is to report a new heterozygous mutation of the RYR1 gene, summarize the similarities and differences of clinical manifestations, genetic characteristics, and pathological changes of CCD and DMD, and provide a new idea for its differential diagnosis.