Mutations in the COL6A1, COL6A2, and COL6A3 genes lead to the musculoskeletal diseases Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD); (for review, see Allamand et al., 2011, Lampe and Bushby, 2005). Here, COL6A3 is linked to Congenital muscular dystrophy, Ullrich type.