UCMD represents the severe form of collagen VI-related congenital muscular dystrophy (COL6-CMD), a rare neuromuscular condition caused by dominant or recessive mutations in one of the genes coding for the collagen VI protein (COL6A1, COL6A2, and COL6A3).23 Here, COL6A3 is linked to Ullrich congenital muscular dystrophy.