Collagen alpha-1（VI） chain is a protein that in humans is encoded by the COL6A1 gene. The collagens are a superfamily of proteins that play a role in maintaining the integrity of various tissues. Collagens are extracellular matrix proteins and have a triple-helical domain as their common structural element. Collagen VI is a major structural component of microfibrils. The basic structural unit of collagen VI is a heterotrimer of the alpha1（VI）, alpha2（VI）, and alpha3（VI） chains. Mutations in the genes that code for the collagen VI subunits result in the autosomal dominant disorder, Bethlem myopathy.