Monoclonal gammopathy with both nemaline myopathy and amyloid myopathy

Neuromuscul Disord. 2017 Oct;27(10):942-946. doi: 10.1016/j.nmd.2017.05.007. Epub 2017 May 11.


Monoclonal gammopathies due to plasma cell dyscrasias can induce diverse rare neuromuscular disorders. Deposition of monoclonal antibody light chains in skeletal muscle causes amyloid myopathy. Monoclonal gammopathy is occasionally associated with sporadic late-onset nemaline myopathy. Here we report a monoclonal gammopathy patient with both sporadic late-onset nemaline myopathy and amyloid myopathy. The diagnoses were based on immunofixation electrophoresis of urine, and serum for free light chain assay, Congo red staining and Thioflavin S staining of muscle biopsies, as well as immunohistochemical staining and electron-microscopic observation. Nemaline myopathy and amyloid myopathy can present in the same patient with monoclonal gammopathy.

Keywords: Amyloid myopathy; Free light chain assay; Immunofixation electrophoresis; Monoclonal gammopathy; Nemaline myopathy; Thioflavin S staining.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Amyloid / analysis
  • Biopsy / methods
  • Humans
  • Immunoglobulins, Intravenous / therapeutic use
  • Male
  • Muscular Diseases / diagnosis
  • Muscular Diseases / drug therapy
  • Muscular Diseases / pathology*
  • Myopathies, Nemaline / diagnosis
  • Myopathies, Nemaline / pathology*
  • Paraproteinemias / diagnosis
  • Paraproteinemias / drug therapy*
  • Paraproteinemias / pathology*


  • Amyloid
  • Immunoglobulins, Intravenous