FAT1 and Facioscapulohumeral dystrophy: Second, among genetic variants in FAT1, a copy number variant (CNV) deleting a putative regulatory element in the FAT1 locus, which has the potential to deplete FAT1 expression in a tissue-specific manner, was enriched not only among FSHD-like patients but also among classical FSHD1 and FSHD2 [14, 119].