The groups of Hoyer et al. (2012), Santen et al. (2012), Tsurusaki et al. (2012), and Van Houdt et al. (2012) identified heterozygous, mainly de novo, mutations in the genes ARID1B (MIM: 614556), ARID1A (MIM: 603024), SMARCA4 (BRG1 [MIM: 603254]), SMARCB1 (SNF5 [MIM: 601607]), and SMARCE1 (MIM: 603111) as the causes of syndromic intellectual disability (ID) and Coffin-Siris syndrome (CSS), and mutations in SMARCA2 (MIM: 600014) as the cause of Nicolaides-Baraitser syndrome (NCBRS). This evidence concerns the gene ARID1A and Coffin-Siris syndrome.