ARID1B and intellectual disability - sparse hair - brachydactyly: For example, BRG1 and BRM mutations (as well as BAF250A/ARID1A and BAF250B/ARID1B mutations) are responsible for Coffin-Siris and Nicolaides-Baraitser syndromes which have similar phenotypic spectrums that include intellectual disability, altered craniofacial features, and distal limb anomalies [4–6].