A number of clinical features of FSHD, including non-muscular symptoms such as hearing loss and retinal vasculopathy [81]–[82], carry the signature of defects in the Wnt/PCP pathway [26], a cascade of tissue polarity regulating genes, involving non-canonical Wnt/Frizzled signalling (core PCP genes) and modulated by the protocadherins FAT and Dachsous [25], [27]. Here, PCDH11X is linked to facioscapulohumeral muscular dystrophy.