Char syndrome


Char syndrome is an autosomal dominant congenital disease caused by mutations in TFAP2B gene which affects the development of the bones of the face as well as the heart and limbs. During embryo development, TFAP2B regulates the production of the protein AP-2β, a transcription factor that is active in the neural crest and helps regulate genes that control cell division and apoptosis. There are at least 10 mutations of this gene that has been identified in people presenting Char syndrome, which alters specific regions of the gene preventing production of the transcription factor and disrupting normal development of embryo structures. People with this condition presents a very distinct facial appearance with flattened cheek bones, flat and broad tip nose, shortened distance between the nose and upper lip, triangular-shaped mouth with tick lips and strabismus. It is also characterized by a patent ductus arteriosus, which is the failure to close the ductus that connects the aorta and pulmonary artery during pre-birth life and may cause many symptoms including breathing issues and heart failure. Abnormalities of hand and finger development have also been reported in people with this condition, including short or absent fifth finger. Others abnormal findings includes supernumerary nipples. These conditions often affect multiple member of a family and there are no report of non-genetic factors that might be related with incidence of this syndrome.