Frameshift Variant in ARID2 in a Chilean Individual with Coffin–Siris Syndrome Phenotype

Coffin-Siris syndrome (CSS) is one of the several causes of intellectual disability (ID) and, since its first description, has posed diagnostic challenges given its variability and phenotypic overlap with other alterations of chromatin-remodeling-associated syndromes. It is genetically heterogeneous, and causative mutations are detected in less than 70% of cases. The different subtypes of the syndrome described to date are caused by mutations in genes that encode subunits of the SWI/SNF chromatin-remodeling complex, which plays an essential role in the regulation of gene expression during embryogenesis. Whole exome sequencing (WES) has allowed the identification of pathogenic mutations in these genes, including