Location of the 14 causative CREBBP mutations found in this study. Only exons are drawn to scale. The histone acetyl transferase domain and the plant homeodomain (PHD)-type zinc finger are indicated according to Kalkhoven et al. (2003), other domains according to Giles et al. (1997). Truncating mutations are in light-grey, missense mutations in dark-grey and the two previously reported mutations in italics.