PCDHGB4 and facioscapulohumeral muscular dystrophy: SMCHD1 has been shown to regulate the PCDH gene clusters, and we find four PCDH genes differentially expressed; PCDH10 and PCDHGA6 were higher in FSHD-Hi, while PCDHGB4 and PCDHGB5 were higher in FSHD-Lo (S4 Table).