Williams syndrome ... (Williams syndrome) - Genes Clip2, ELN, GTF2I, GTF2IRD1, Limk1 and NCF1.
Williams syndrome is a developmental disorder that affects many parts of the body. This disease is characterized by mental retardation or mild to moderate learning disabilities, personality characteristics unique, distinctive facial features and cardiovascular problems.
People with Williams syndrome often have difficulty with visual-spatial skills such as drawing and assembling puzzles, but tend to do well tasks involving spoken language, music and memorization. Are common disorders such as attention deficit disorder, anxiety disorders and fobiasLos young children with Williams syndrome have characteristic facial features including a broad forehead, a short nose with wide tip, prominent cheeks and a wide mouth with full lips. Many affected people have dental problems with small, widely spaced, crooked, or missing teeth. The face appears more elongated and gaunt in older children and adults. Other additional signs and symptoms include abnormal connective tissue such as joint problems and skin soft, loose, hypercalcemia in childhood, developmental delays, coordination problems and short stature. There may also be problems affecting the eyes and vision, digestive tract and urinary tract.
In people with Williams syndrome, it occurs frequently a form of cardiovascular disease, aortic stenosis supravalvar. If this condition is not treated, the narrowing of the aorta can lead to circulatory problems that occur with shortness of breath, chest pain and heart failure. Other problems with the heart and blood vessels, including hypertension.
Williams syndrome, is caused by the deletion of genetic material from a specific region of chromosome 7. The deleted region includes 26 to 28 genes.
The Clip2 genes, ELN, GTF2I, GTF2IRD1, Limk1 and NCF1 are some of the genes that are normally eliminated in people with Williams syndrome.
The Clip2 gene, located on the long arm of chromosome 7 (7q11.23), encoding CAP- GLY (CLIP -115) containing the protein - binding protein 2. This protein is found predominantly in the brain, which probably plays a role in the structure and normal function of nerve cells. Within cells, it is believed that this protein is associated with microtubules that maintain cell shape, involved in the process of cell division, and are essential for transporting material within cells. The loss of one copy of this gene may contribute to some of the characteristic features of Williams syndrome, including unique behavioral traits and other nervous system related symptoms. A deletion of this gene probably alters the normal regulation of the cytoskeleton and affect the structure of nerve cells in the brain.
ELN gene, located on the long arm of chromosome 7 (7q11.23), encoding tropoelastin protein. Multiple copies of this protein adhering to each other to form elastin, the main component of elastic fibers that provide strength and flexibility to connective tissue. The loss of a copy of the ELN gene reduces the production of elastin, which interrupts the normal structure of elastic fibers in many connective tissues.
The GTF2I gene, located on the long arm of chromosome 7 (7q11.23) encodes two proteins, BAP- 135 and TFII -I. The BAP- 135 protein, active in B cells, is involved in the normal function of the immune system, relaying chemical signals that enable B cells respond to potentially harmful invaders. TFII - I protein is a transcription factor involved in coordination of cell growth and division, and may also play a role by controlling the flow of calcium into cells. The loss of one copy of the gene in every cell, results in mental retardation, to dental anomalies and problems typical embodiment of t visual and spatial areas such as writing and drawing.
The GTF2IRD1 gene, located on the long arm of chromosome 7 (7q11.23), encodes a protein transcription factor. Although the exact function is unknown, the GTF2IRD1 gene is active in many tissues. It seems to be particularly important for gene regulation in the brain and skeletal muscles. Studies suggest that this gene plays a role in craniofacial development. L to loss of one copy of this gene gives rise to distinctive facial features, dental anomalies and problems related to visual and spatial tasks such as writing and drawing.
The LIMK1 gene, located on the long arm of chromosome 7 (7q11.23), encodes a protein which is highly active in the brain, where it is believed to be involved in the development of nerve cells. It is believed that this protein may play an important role in visuospatial recognition. The protein helps control the organization of actin filaments required for several normal cellular functions such as cell division, cell movement, maintenance of cell shape, transport proteins and other molecules within cells, and chemical signaling between cells. The loss of one copy of this gene contributes to the characteristic problems with visual and spatial tasks such as writing and drawing. However, other studies have not found this relationship. Probably a deletion of this gene affects the development and function of nerve cells in the brain. It has not been determined how a reduction in the amount of protein Limk1 can relate to the specific shortcomings in Williams syndrome.
The NCF1 gene, located on the long arm of chromosome 7 (7q11.23), encodes a protein called neutrophil cytosolic factor 1 (also known as p47 - phox). This protein is a subunit of a group of proteins that form the NADPH oxidase complex, which plays an essential role in the immune system. NADPH oxidase acts primarily on phagocytes, destroying foreign invaders such as bacteria and fungi. Lso is recognized that regulates the activity of neutrophils, that play a role in the inflammatory response reducing injury in the body. The NCF1 gene is found in a region of chromosome 7 that is removed frequently in people with Williams syndrome, so by eliminating a portion of chromosome 7, some people with the disease lose NCF1 a copy of the gene.
Williams syndrome is considered an autosomal dominant disease because an altered copy of chromosome 7 in each cell is sufficient to cause disruption. In a small percentage of cases, people with Williams syndrome inherited chromosomal deletion of a parent with the disease. Most cases of the disease are not inherited, being caused by random events during the formation of reproductive cells in a parent of an affected person. These cases occur in people with no history of disease in your family.
Tests in IVAMI: in IVAMI perform the detection of mutations associated with Williams syndrome, by complete PCR amplification of the exons of Clip2, ELN, GTF2I, GTF2IRD1, LIMK1 and NCF1, respectively, and subsequent sequencing genes.
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).