ARID1A and Coffin-Siris syndrome: ARID1A (the AT‐rich interaction domain 1A, also known as BAF250a), the largest subunit of the SWI/SNF chromatin remodeling complex, has been reported that its mutations are closely related to Coffin–Siris syndrome (CSS), which is characterized by intellectual disability, growth deficiency and microcephaly.14, 15, 16