Congenital myopathies


Yiş U., Polat A. İ., Diniz G.

in: Clues for Differential Diagnosis of Neuromuscular Disorders, Diniz G., Editor, Springer Nature, Aarau, pp.219-248, 2023

  • Publication Type: Book Chapter / Chapter Vocational Book
  • Publication Date: 2023
  • Publisher: Springer Nature
  • City: Aarau
  • Page Numbers: pp.219-248
  • Editors: Diniz G., Editor
  • Dokuz Eylül University Affiliated: Yes

Abstract

Congenital myopathies form a clinically, genetically, and morphologically heterogeneous group of neuromuscular disorders. They generally present with hypotonia (±muscle weakness) in the neonatal/infantile period, in some cases, the first symptoms occur in the juvenile or adult period. They occur due to structural defects within muscle fibers, affecting the contractile matrix, excitation-contraction coupling, T-tubules, and sarcoplasmic reticulum while muscle membrane stability is spared. They are also a type of neuromuscular disorder, pathologically characterized by myopathic changes, such as differences in myofiber sizes, internalized nuclei, and the presence of degenerating fibers. Structural abnormalities in a muscle biopsy are classified according to abnormally located organelles and intracellular bodies. These classifications include nemaline myopathy, central core disease, multi-mini core myopathy, centronuclear myopathy, congenital fiber-type disproportion and others. With developments in the field of molecular genetics, these diseases have been associated with more and more genes. Thus, pathological classification and a classification based on molecular genetics are used together. This chapter addresses the congenital myopathies and its subgroups through an overview of the disorder and their pathological and genotype features.