Clinical and genetic characteristics and an algorithm for the differential diagnosis of progressive muscular dystrophies that manifest after a period of normal motor development

Background. Progressive muscular dystrophies (PMD) are a group of genetically heterogeneous diseases that manifest in the age range from early childhood to adulthood. Depending on the predominant topography of the muscular lesion, there are: limb-girdle, distal, oculopharyngeal, facial-shoulder-scapular-peroneal variants of PMD.Aim. Creation of algorithms for the differential diagnosis of PMD with multiple topography of muscle lesions.Materials and methods. We observed 192 patients aged 1.5 to 66 years with PMD with a debut after a period of normal motor development. The diagnosis was established on the basis of genealogical analysis, neurological examination, assessment of non-muscular manifestations, results of instrumental, biochemical molecular genetic studies.Results. Four groups of patients were identified, differing in the topography of muscle damage and 19 genetic variants of PMD were diagnosed. An algorithm for diagnosing PMD that manifest after a period of normal motor development is proposed, which is based on the frequency of occurrence of individual genetic variants and their proportion in the analyzed sample, the presence of major mutations in causal genes, the features of phenotypic characteristics, the gender of the patient and the possibility of conducting etiopathogenetic therapy developed by for some genetic variants.Conclusion. The use of the proposed algorithm in clinical practice can significantly reduce the economic and time costs for confirmatory molecular genetic diagnosis, and promptly recommend etiopathogenetic therapy for some genetic variants of this group of diseases.