A congenital myopathy of the musculoskeletal system that covers a wide spectrum of phenotypes and is caused by pathogenic variants in the skeletal muscle beta-Tropomyosin gene. These variants lead to a variety of overlapping adult onset and congenital myopathies characterized by muscle weakness, amyotrophy, hypotonia, myopathic facies, scoliosis, and sometimes contractures among other phenotypes. Histologic findings on skeletal muscle biopsy are variable with nemaline and intranuclear bodies, cap-like lesions, core-like lesions, fiber-type disproportion, and dystrophic features all observed to some degree. [ https://clinicalgenome.org/affiliation/40031/ http://www.ncbi.nlm.nih.gov/pubmed/23413262 ]
Synonyms: congenital myopathy related to TPM2 TPM2 myopathy TPM2-related myopathy autosomal dominant TPM2-related myopathy
Term information
rare, inferred_rare, clingen
The most penetrant phenotype among all of the TPM2-related myopathy disease entities is muscular weakness. Notably, other developmental disorders such as distal arthrogryposis have also been reported in association with TPM2 mutations. While phenotypic and mechanistic similarities demonstrate that the TPM2-related myopathy disorders share a similar pathogenic mechanism, these developmental disorders characterized primarily by contractures are not considered part of the same spectrum as this entity.