This report describes general characteristics of the group of diseases classified as centronuclear myopathy (CNM). Centronuclear myopathy is a genetically heterogeneous disorder, with multiple implicated genes and mapped loci. A list of CNM subtypes, as defined by OMIM, may be found by following the link in the "OMIM phenotypic series" section, below.
[updated Dec. 2015 by FlyBase; FBrf0222196]
Centronuclear myopathy is a congenital myopathy characterized by slowly progressive muscular weakness and wasting; the disorder involves mainly limb girdle, trunk, and neck muscles but may also affect distal muscles; ptosis (drooping eyelid) and limitation of eye movements may occur. Age of onset varies, from childhood to young adulthood. (Bitoun et al., 2005, pubmed:16227997). [from MIM:160150; 2015.12.16]
There are autosomal dominant, autosomal recessive, and X-linked forms of the disorder.
Centronuclear myopathy is a genetically heterogeneous disorder, with multiple implicated genes. [from MIM:160150; 2015.12.16]
"Centronuclear" refers to the position of the nuclei in the multinucleated muscle fiber cells. In normal muscle cells, the nuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, the nuclei are often clustered within the center of the muscle cell (Folker and Baylies, 2013; pubmed:24376424).
Histopathologic features include high frequency of centrally located nuclei in a large number of extrafusal muscle fibers (which is the basis of the name of the disorder), radial arrangement of sarcoplasmic strands around the central nuclei, and predominance and hypotrophy of type 1 fibers (Bitoun et al., 2005, pubmed:16227997). [from MIM:160150; 2015.12.16]
