Enables protein homodimerization activity. Involved in inactivation of X chromosome by heterochromatin assembly. Acts upstream of or within dosage compensation by inactivation of X chromosome. Located in Barr body. Is expressed in several structures, including blastocyst and genitourinary system. Human ortholog(s) of this gene implicated in facioscapulohumeral muscular dystrophy 2. Orthologous to human SMCHD1 (structural maintenance of chromosomes flexible hinge domain containing 1). [provided by Alliance of Genome Resources, Apr 2022]