FAT Atypical Cadherin 1 (FAT1) is also near the FSHD locus and because loss-of-function mutations were found in patients who had D4Z4 copy numbers close to the normal range, they were suggested to cause FSHD, despite the disease dominant transmission [106] (Fig. 1). This evidence concerns the gene FAT1 and facioscapulohumeral muscular dystrophy.