Desmin (DES) is a class-III intermediate filament found in muscle cells. In adult striated muscle they form a fibrous network connecting myofibrils to each other and to the plasma membrane from the periphery of the Z-line structures. Defects in DES are the cause of several human diseases, such as myopathy myofibrillar type 1 (MFM1), cardiomyopathy dilated type 1I (CMD1I) and neurogenic scapuloperoneal syndrome Kaeser type (Kaeser syndrome). MFM1 is a neuromuscular disorder characterised by skeletal muscle weakness associated with cardiac conduction blocks, arrhythmias, restrictive heart failure, and by myofibrillar destruction with intracytoplasmic accumulation of desmin-reactive deposits in cardiac and skeletal muscle cells. CMD1I is a disorder characterised by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Kaeser syndrome is an autosomal dominant disorder with a peculiar scapuloperoneal distribution of weakness and atrophy.