Nemaline myopathy

Jennifer Baccon MD PhD (

Dr. Baccon of Akron Children's Hospital and Northeast Ohio Medical University has no relevant financial relationships to disclose.

Harvey B Sarnat MD FRCPC MS, editor. (

Dr. Sarnat of the University of Calgary has no relevant financial relationships to disclose.

Originally released December 16, 1994; last updated November 7, 2020; expires November 7, 2023


The full complement of known mutations that cause nemaline myopathy is presented. This review also highlights literature that discusses the cardiac manifestations of this disease.

Key points


• Nemaline myopathy is probably the most common of the congenital myopathies.


• Nemaline myopathy can present at any age with proximal muscle weakness, respiratory insufficiency, or bulbar dysfunction.


• Childhood forms of nemaline myopathy are caused by mutations in numerous genes encoding muscle thin filaments.


• Adult forms of nemaline myopathy can be more rapidly progressive and may be caused by immune dysregulation.

Historical note and terminology

Nemaline myopathy was first described in 1963 by investigators from the United States and Canada (Conen et al 1963; Shy et al 1963). Nemaline myopathy is defined by a particular ultrastructural change on muscle biopsy: the finding of thread-shaped structures in muscle fibers, which are known as nemaline bodies, or rods (from the Greek nema, meaning thread).

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