Both of these genes are composed of 8 exons, and are from a conserved family of genes that share a common DNA-binding domain, the T-box. The proteins encoded by these genes are transcriptin factors involved in the regulation of developmental processes. Mutations in these genes have been associated with cardiovascular defects, Atrioventricular septal defects, Ventricular septal defects, Tetralogy of Fallot, Velocardiofacial syndrome and holt-Oram syndrome.