Desmin

Desmin is a

Desmin was first described in 1976,[16] first purified in 1977,^[17] the gene was cloned in 1989,^[6] and the first knockout mouse was created in 1996. The function of desmin has been deduced through studies in knockout mice. Desmin is one of the earliest protein markers for muscle tissue in embryogenesis as it is detected in the somites.^[12][18] Although it is present early in the development of muscle cells, it is only expressed at low levels, and increases as the cell nears terminal differentiation. A similar protein, vimentin, is present in higher amounts during embryogenesis while desmin is present in higher amounts after differentiation. This suggests that there may be some interaction between the two in determining muscle cell differentiation. However desmin knockout mice develop normally and only experience defects later in life.^[13] Since desmin is expressed at a low level during differentiation another protein may be able to compensate for desmin's function early in development but not later on.^[19]

In adult desmin-null mice, hearts from 10 week-old animals showed drastic alterations in muscle architecture, including a misalignment of myofibrils and disorganization and swelling of mitochondria; findings that were more severe in cardiac relative to skeletal muscle. Cardiac tissue also exhibited progressive necrosis and calcification of the myocardium.

Desmin-related myofibrillar myopathy (DRM or desminopathy) is a subgroup of the myofibrillar myopathy diseases ^[27] and is the result of a mutation in the gene that codes for desmin which by changing the protein structure ^[28] prevents it from forming protein filaments, and rather, forms aggregates of desmin and other proteins throughout the cell.^[8][12] Desmin (DES) mutations have been associated with restrictive,^[29] dilated,^[30][31] idiopathic,^[32][33] arrhythmogenic ^{[34][35][36][37]} and non-compaction cardimyopathy.^[38][39] Even within the same family the observed cardiac phenotype could be broad and diverse. The N-terminal part of the 1A desmin subdomain is a genetic hot spot region for mutations affecting filament assembly.^[40][41] Some of these DES mutations cause an aggregation of desmin within the cytoplasm.^[41][42][43] Some mutations like p.A120D or p.R127P were discovered in families, where several members had sudden cardiac death.^[44] In addition, DES mutations cause frequently cardiac conduction diseases.^[45]

Desmin has been evaluated for role in assessing the depth of invasion of