Here I present: “Char Syndrome”, Victor McKusick, Mendelian Inheritance in Man’, 1966. 炭綜合症。(CHAR) icd10=Q87.8
INTRODUCTION.
Char syndrome (CHAR) is an autosomal dominant disorder characterized by patent ductus arteriosus, facial dysmorphism, and abnormal fifth digits of the hands
Char syndrome is a 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. It was first described by Florence Char in 1978.
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 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, 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. Other abnormal findings include supernumerary nipples.
There is evidence that Char syndrome (CHAR) is caused by heterozygous mutation in the TFAP2B gene on cytogenetic location 6p12.3 and genomic coordinates 6:50,818,355-50,847,619. The screenshot of the TFAPA2B gene 29,265 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides TFAPA2B in the 6p12.3 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 6:49,785,660 | PGK2 | Phosphoglycerate kinase-2 (testicular PGK) |
| 6:49,834,257 | CRISP1 | Cysteine-rich secretory protein 1 |
| 6:49,960,249 | DEFB114 | Defensin, beta, 114 |
| 6:50,713,526 | TFAP2D | Transcription factor AP2-delta |
| 6:50,818,355 | TFAP2B | Transcription factor AP2-beta |
| 6:51,615,299 | PKHD1 | PKHD1 ciliary IPT domain containing fibrocystin/polyductin |
| 6:51,800,001 | MRT24 | Intellectual developmental disorder, autosomal recessive 24 |
| 6:52,144,349 | MIR206 | Micro RNA 206 |
| 6:52,146,814 | LINCMD1 | Long intergenic noncoding RNA, muscle differentiation 1 |
| 6:52,148,923 | MIR133B | Micro RNA 133B |
