Sunday 20 March 2005
Congenital myopathies are clinical and genetic heterogeneous disorders characterized by skeletal muscle weakness ranging in severity.
Three major forms have been identified:
intranuclear rod myopathy
Nemaline myopathy is the most common of these myopathies and is further subdivided into seven groups according to severity, progressiveness, and age of onset.
At present, five genes have been linked to congenital myopathies.
alpha- and beta-tropomyosin (TPM3 and TPM2)
troponin T (TNNT1)
Their protein products are all components of the thin filament of the sarcomere. The mutations identified within these genes have varying impacts on protein structure and give rise to different forms of congenital myopathies.