In inclusion body myositis (IBM), there is muscular amyloidogenesis and inflammation. A related disorder is due to alterations in the ubiquitin pathway involving the valsolin-containing protein leading to IBM, dementia and Paget's disease. Alteration in the dystrophin glycoprotein complex leads to several muscular dystrophies (MD), and the pathogenesis of dystrophin related MD as well as certain limb girdle MD are discussed. Therapeutic strategies involving inhibition of proteolytic cascades as well as inhibition of a negative regulator of muscle growth (myostatin) are briefly introduced. Finally, molecular aspects of the most common form of adult myopathy, myotonic MD, are discussed. This disease is caused by an aberrant splicing mechanism and interference thereof may be useful in designing therapeutic strategies.