ARID1B and Coffin-Siris syndrome: For instance, the SMARCB1, SMARCA4, SMARCE1, ARID1A, and ARID1B genes encode subunits of the BAF complex (also known as the SWI/SNF complex in yeast), and they are responsible for 55–70% of Coffin–Siris syndrome cases, where microcephaly can manifest as one of the phenotypes (Kosho et al., 2014; Vergano et al., 2021).