New type of histological abnormalities in congenital nemaline myopathies

French clinicians report, in five patients with congenital rod myopathy (also called nemaline), histological lesions in the form of dense protein masses:

  • none of the patients were related,
  • in three of them pathological variants of the NEB gene encoding nebulin were identified,
  • in another, the TPM2 gene encoding tropomyosin-2 was involved,
  • the clinical phenotype was not specific with global motor deficit and moderate restrictive pulmonary syndrome, without associated cardiac involvement,
  • the dense masses observed by electron microscopy were composed of Z-streak sarcomeric proteins and were different from rods.


Congenital Nemaline Myopathy with Dense Protein Masses. Bevilacqua JA, Malfatti E, Labasse C, Brochier G, Madelaine A, Lacène E, Doray B, Laforêt P, Eymard B, Rendu J, Romero NB. J Neuropathol Exp Neurol. 2022 Feb 9:nlab139.