A number of mutations that cause Cornelia de Lange Syndrome [CDLS2 (MIM: 300590)] have been mapped to the gene encoding the core cohesin subunit, SMC1A, which encodes the SMC1A protein (Musio et al. 2006; Borck et al. 2007; Deardorff et al. 2007). This evidence concerns the gene SMC1A and Cornelia de Lange syndrome.