SMCHD1 and Facioscapulohumeral dystrophy: Despite this failure to recover DNA methylation at D4Z4, restoration of SMCHD1 levels in FSHD muscle cell cultures represses DUX4 expression in a DNA methylation-independent manner13,14, suggesting that DNA methylation-independent chromatin repressor complexes are recruited to D4Z4 through SMCHD1.