Collagen VI-related myopathy include severe Ullrich congenital muscular dystrophy (UCMD) and milder Bethlem myopathy. Mutations in each of the three collagen VI genes COL6A1, COL6A2, and COL6A3 cause these diseases. Recently, additional phenotypes, autosomal recessive myosclerosis with mutations in COL6A2 have been reported. Collagen VI is an important component of the extracellular matrix which forms a microfibrillar network that is found in close association with the cell and surrounding basement membrane. Thus, collagen VI mutations result in disorders with combined muscle and connective tissue involvement, including weakness, joint and contractures, and abnormal skin findings.
