Heterozygous mutations in SMCHD1 are found in two distinct human disorders: loss of function mutations in facioscapulohumeral muscular dystrophy (FSHD)(Lemmers et al., 2012), and potentially gain of function mutations in the rare craniofacial disorder Bosma arhinia and microphthalmia (BAMS)(Gordon et al., 2017; Shaw et al., 2017; Gurzau et al., 2018). Here, SMCHD1 is linked to facioscapulohumeral muscular dystrophy.