Over D4Z4 contraction, FSHD has also been associated with the occurrence of detrimental variants within the sequences of Structural Maintenance of Chromosomes flexible Hinge Domain–containing protein 1 (SMCHD1, 18p11.32) and DNA Methyltransferase 3 Beta (DNMT3B, 20q11.21) Ligand Dependent Nuclear Receptor Interacting Factor 1 (LRIF1, 1p13.3) genes. This evidence concerns the gene SMCHD1 and facioscapulohumeral muscular dystrophy.