COL6A3 and Ullrich congenital muscular dystrophy: Deficiency of ColVI due to mutations in COL6A1, COL6A2, or COL6A3 gives rise to three main muscle disorders, Ullrich congenital muscular dystrophy (UCMD, MIM #254090) (Ullrich, 1930; Camacho Vanegas et al., 2001), Bethlem myopathy (BM, MIM #158810) (Bethlem and Wijngaarden, 1976), and myosclerosis myopathy (MIM #255600) (Merlini et al., 2008b).