Differential diagnosis of Duchenne muscular dystrophy

Abstract

Duchenne muscular dystrophy (DMD) is a disease with an X-linked recessive type of inheritance, belonging to a group of disorders with primary muscle damage, caused by pathogenic variants in the DMD gene and associated with dysfunction of the dystrophin protein. Since DMD is manifested by the gradual development of progressive, mainly proximal muscle weakness, the differential diagnosis is primarily carried out in the group of diseases with muscle damage - myopathies. Among these diseases, the leading candidates for differential diagnosis are hereditary myopathies (limb-girdle muscular dystrophies, facioscapulohumeral dystrophy, congenital muscular dystrophies, glycogenoses - the most common juvenile form of glycogenosis type II (Pompe disease)) and, much less often, congenital myopathies and other conditions of neuromuscular diseases). When conducting a differential diagnosis in a child with suspected DMD, the age of the onset of the disease, early initial clinical manifestations and the development of symptoms as they grow, genealogical analysis, laboratory tests (the level of creatine kinase, aspartate aminotransferase, alanine aminotransferase in blood serum), instrumental (electromyography, magnetic resonance imaging of the brain and muscles) and molecular genetics (polymerase chain reaction, multiplex ligation-dependent probe amplification, next-generation sequencing, Sanger sequencing, etc.) of studies, and in some cases, muscle biopsy data. Knowledge of the nuances of the differential diagnosis allows establishing a genetic diagnosis of DMD as early as possible, which is extremely important for the formation of the prognosis of the disease and the implementation of all available treatment methods, including pathogenetic therapy, and is also necessary for medical and genetic counselling of families with DMD patients.