COL6A3 and Congenital muscular dystrophy, Ullrich type: Mutations in the COL6A1, COL6A2, and COL6A3 genes cause collagen VI-related myopathies (COL6-RM) that include Ullrich congenital muscular dystrophy (UCMD), Bethlem myopathy (BM), and myosclerosis myopathy (MM) [7].