This report describes general characteristics of the group of diseases classified as nemaline myopathy (NEM). Nemaline myopathy is a genetically heterogeneous disorder, with multiple genes and mapped loci. A comprehensive list of subtypes, as defined by OMIM, can be found by following the link in the 'Related Diseases section', 'OMIM phenotypic series' sub-section, below. The associated table includes links to more detailed reports for subtypes that have been investigated using fly models.
[updated Jul. 2017 by FlyBase; FBrf0222196]
Nemaline myopathy is a form of congenital myopathy; the clinical phenotype is highly variable, with differing age at onset and of severity. Muscle weakness typically involves proximal muscles, with involvement of the facial, bulbar, and respiratory muscles (Ilkovski et al., 2001; pubmed:11333380). Typical nemaline myopathy is the most common form, presenting as infantile hypotonia and muscle weakness. It is slowly progressive or nonprogressive, and most adults achieve ambulation. The severe form of the disorder is characterized by absence of spontaneous movement or respiration at birth, arthrogryposis, and death in the first months of life. Much less commonly, late-childhood or adult-onset can occur (Wallgren-Pettersson et al., 1999, pubmed:10619714; Sanoudou and Beggs, 2001, pubmed:11516997). [from MIM:161800; 2017.07.24]
Nemaline myopathy is a genetically heterogeneous disorder. [from MIM:161800; 2017.07.24]
Adult-onset nemaline myopathy is usually not familial and may represent a different disease (Wallgren-Pettersson et al., 1999, pubmed:10619714; Sanoudou and Beggs, 2001, pubmed:11516997). [from MIM:161800; 2017.07.24]
Multiple genes associated with nemaline myopathy encode proteins required for normal sarcomere structure (FBrf0246264 and references cited therein).
Nemaline myopathy is characterized by abnormal thread- or rod-like structures in muscle fibers on histologic examination ('nema' is Greek for 'thread'). [from MIM:161800; 2017.07.24]
