Saethre-Chotzen syndrome ... - (Saethre-Chotzen syndrome) - Genes TWIST1 and FGFR2.
Saethre-Chotzen syndrome The genetic alteration is characterized by craniosynostosis. This early fusion prevents the skull to grow normally, affecting the shape of the head and face. Most people with this syndrome have fused prematurely skull bones along the coronal suture. Other parts of the skull may also be malformed. This alteration can result in a misshapen head, a high forehead, a low front line, drooping eyelids, widely spaced eyes, and a broad nasal bridge. There may be facial asymmetry. Most people with Saethre-Chotzen syndrome also have small, unusually shaped ears. Signs and symptoms of Saethre-Chotzen syndrome vary widely, even among people affected in the same family. Such alteration may mild abnormalities hands and feet, as the fusion of the skin between the second and third finger on each hand and a finger foot large or duplicated. Although most people with this syndrome have normal intelligence, others may have difficulty learning and development. Signs and Less common symptoms include short stature, Vertebral, hearing loss and heart defects.
This process is due to mutations in the gene TWIST1, located on the short arm (p) of chromosome 7 (7p21.2). This gene encodes a protein that plays an important role in the initial development, because it is a transcription factor, active in cells that give rise to the bones, muscles and other tissues of the skull and face, as well as in the development of the extremities.
They have identified more than 80 mutations in the gene TWIST1, causing Saethre-Chotzen of the syndrome. Mutations in the gene TWIST1 prevent any functional protein is produced. The shortage of the protein affects the development and maturation of cells in the skull, the face and extremities. These abnormalities are the basis of the signs and symptoms of the syndrome, including premature fusion of certain skull bones.
They have been reported some cases of the syndrome resulting from mutations in FGFR2 gene. This gene, located on the long (q) arm of chromosome 10 (10q26), encodes a protein called fibroblast growth factor-2. This protein is one of the four factors of fibroblast growth, which are proteins that are involved in important processes such as cell division, regulation of cell growth and maturation, the formation of blood vessels, wound healing, and embryonic development. This protein interacts with specific growth factors outside the cell to receive signals that help the cell to respond to its environment. When the growth factors bind to the protein, the receptor triggers a cascade of chemical reactions that instruct the cell to undergo certain changes, such as maturation to take specialized functions. This protein plays an important role in bone growth particularly during embryonic development.
This syndrome is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to cause disease. In some cases, an affected person inherits the mutation from an affected parent. Other cases may be the result of new mutations in the gene. These cases occur in people with no history of disease in your family.
Tests in IVAMI: in IVAMI perform detection of mutations associated with Saethre-Chotzen syndrome, by complete PCR amplification of exons TWIST1 and FGFR2, respectively and subsequent sequencing gene.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).