APA Dictionary of Psychology

a rare genetic condition characterized by premature closure of one or more of the cranial sutures, usually involving the coronal suture (see craniosynostosis syndrome), which affects the growth and symmetry of the head and face. Other features may include webbing of the fingers and toes, short stature, delayed development, and learning difficulties. Most cases are caused by mutations in the TWIST1 gene. In a small number of cases, when the cause is a chromosomal deletion instead of a mutation within the TWIST1 gene, children with Chotzen's syndrome are much more likely to have intellectual developmental disorder, developmental delay, and learning difficulties. It is thought that a loss of other genes on chromosome 7 may be responsible for these additional features. Also called acrocephalosyndactyly Type III; Saethre–Chotzen syndrome. [F. Chotzen, German physician]