D4Z4 location near telomeres could also facilitate mis‐regulation of DUX4, as telomeric shortening associates with epigenetic changes and increased DUX4 expression (Stadler et al, 2013), providing a mechanism for non‐genetic heterogeneity, asymmetric muscle weakness and adult onset in FSHD. This evidence concerns the gene DUX4 and facioscapulohumeral muscular dystrophy.