TPM3-related myopathy is a disorder of the musculoskeletal system that covers a wide spectrum of phenotypes and is caused by pathogenic variants in the skeletal muscle γ-Tropomyosin gene. These variants lead to a variety of overlapping adult onset and congenital myopathies characterized by muscle weakness, hypotonia, motor delay, myopathic facies, scoliosis, and sometimes respiratory involvement. Histologic findings on skeletal muscle biopsy are variable with nemaline and intranuclear bodies, cap-like lesions, fiber-type disproportion, and dystrophic features even in patients with the same mutation. [ http://www.ncbi.nlm.nih.gov/pubmed/24692096 https://clinicalgenome.org/affiliation/40031/ ]
Synonyms: TPM3 myopathy congenital myopathy related to TPM3 TPM3-related myopathy
Term information
rare, inferred_rare, clingen
The most penetrant phenotype among all of the TPM3-related myopathy disease entities is muscular weakness. While nemaline myopathy is the most common presentation, several other myopathies have been reported in association with TPM3 mutations. The absence of clearly defined and/or distinct differences in molecular mechanism, coupled with noted phenotypic variability (both intra- and inter-familial) for individual variants, indicates that these entities are part of the same clinical spectrum.