Char syndrome is an

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

congenital disease A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can r ...

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 An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

, TFAP2B regulates the production of the protein AP-2β, a

transcription factor In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...

that is active in the

neural crest Neural crest cells are a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm germ layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, per ...

and helps regulate genes that control

cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...

and

apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...

. There are at least 10 mutations of this gene that have 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 present 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 ''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has ...

, which is the failure to close the ductus that connects the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes ...

and

pulmonary artery A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and t ...

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. Other abnormal findings include supernumerary nipples. These conditions often affect multiple members of a family and there are no reports of non-genetic factors that might be related with incidence of this syndrome. It was first described by Florence Char in 1978.

References

{{Reflist Congenital disorders