FRG1 and facioscapulohumeral muscular dystrophy: Among the genes up-regulated in FSHD, FRG1 (FSHD region gene 1) is a likely contributor to FSHD pathogenesis since it is required for normal muscle development [24] and its over-expression in mice, Xenopus and C. elegans causes an FSHD-like phenotype [24]–[27].