CERS1 and facioscapulohumeral muscular dystrophy: Across multiple muscle diseases, including DMD, Becker muscular dystrophy (BMD), Emery-Dreifuss muscular dystrophy (EDMD), and facioscapulohumeral muscular dystrophy (FSHD), we found an almost universal up-regulation of sphingolipid biosynthetic enzymes, with the exception of CERS1 (Fig. 1B).