Entry - #135900 - COFFIN-SIRIS SYNDROME 1; CSS1 - OMIM

Coffin-Siris syndrome is a multiple malformation syndrome characterized by impaired intellectual development associated with coarse facial features, hypertrichosis, sparse scalp hair, and hypoplastic or absent fifth fingernails or toenails. Other more variable features may include poor overall growth, craniofacial abnormalities, spinal anomalies, and congenital heart defects (review by Vergano and Deardorff, 2014). Mutations in the ARID1B gene are the most common cause of Coffin-Siris syndrome (Wieczorek et al., 2013).

Genetic Heterogeneity of Coffin-Siris Syndrome

Forms of Coffin-Siris syndrome have been shown to be caused by mutations in genes encoding subunits of the SWI/SNF complex, also known as the BAF complex, which functions as a chromatin remodeling factor. These include CSS2 (614607), caused by mutation in the ARID1A gene (603024); CSS3 (614608), caused by mutation in the SMARCB1 gene (601607); CSS4 (614609), caused by mutation in the SMARCA4 gene (603254); CSS5 (616938), caused by mutation in the SMARCE1 gene (603111); CSS6 (617808), caused by mutation in the ARID2 gene (609539); CSS7 (618027), caused by mutation in the DPF2 gene (601671); CSS8 (618362), caused by mutation in the SMARCC2 gene (601734); CSS9 (615866), caused by mutation in the SOX11 gene (600898); CSS10 (618506), caused by mutation in the SOX4 gene (184430); CSS11 (618779), caused by mutation in the SMARCD1 gene (601735); and CSS12 (619325), caused by mutation in the BICRA gene (605690).

A similar phenotype, Nicolaides-Baraitser syndrome (NCBRS; 601358), is also caused by mutation in a subunit of this complex, i.e., SMARCA2 (600014).