What causes Coffin-Siris syndrome ?
What causes Coffin-Siris syndrome? Coffin-Siris syndrome is caused by a change (mutation) in either the ARID1A, ARID1B, SMARCA4, SMARCB1, or SMARCE1 gene. Exactly how these gene mutations result in the symptoms of Coffin-Siris syndrome is not known, however it is thought that the mutations affect how genetic material is packaged in the cell. Coffin-Siris syndrome is an autosomal dominant condition; as only one gene mutation is needed to cause the syndrome. It usually occurs for the first time in a family due to a new mutation.  In some cases, no genetic mutation can be identified and the cause of Coffin-Siris syndrome in the family remains unknown.