Coffin-Siris Syndrome 1, also known as coffin-siris syndrome, is related to coffin-siris syndrome 5 and coffin-siris syndrome 4. An important gene associated with Coffin-Siris Syndrome 1 is ARID1B (AT-Rich Interaction Domain 1B), and among its related pathways/superpathways are Gene expression (Transcription) and RNA Polymerase I Promoter Opening. Affiliated tissues include bone and heart, and related phenotypes are coarse facial features and thick eyebrow