Menkes syndrome ... (Menkes syndrome) - Gen atp7a.
Menkes syndrome is a disorder that affects copper concentrations in the body. It is characterized by sparse and curly hair, hypotonia, seizures, failure to gain weight, stunted growth, impaired nervous system, developmental delay and intellectual disability. In general, people with Menkes syndrome symptoms begin to develop during childhood and often do not live beyond 3 years old. In rare cases, symptoms begin during infancy.
Menkes syndrome is caused by mutations in the ATP7A gene, located on the long arm of chromosome X (Xq21.1). This gene encodes a protein that is important for regulating the concentrations of copper in the body. Copper is necessary for many cellular functions, but it is toxic when present in excessive amounts. The protein is found throughout the body except liver cells. In the small intestine, this protein helps to control the absorption of copper from food. In other cells, it has a dual function and acts as a link between two cellular locations. In the Golgi apparatus, the protein delivers copper to certain enzymes critical to the structure and function of the bones, skin, hair, blood vessels and nervous system.
They have identified more than 150 mutations in the gene atp7a in people with Menkes syndrome. Many of these mutations of the gene deleted, which results in a shortened protein. Other mutations inserted nucleotides in the gene or single nucleotide change. These mutations prevent the synthesis of a functional protein. As a result, the copper absorption of food resulting in a poor distribution of copper to the body 's cells is altered. Copper accumulates in some tissues such as the small intestine and kidneys, whereas the brain and other tissues have low concentrations of copper. The decreased supply of copper may reduce the activity of numerous enzymes that are necessary for the structure and function of the bones, skin, hair, blood vessels, and nervous system.
Menkes syndrome is a recessive inherited with X - linked pattern. The gene associated with this change is on the X chromosome in males, an altered copy of the gene in each cell is sufficient to cause disease. In women, a mutation would have to happen in both copies of the gene to cause the disease. Because it is unlikely that women have two altered copies of this gene, males are affected by X - linked recessive disorders much more frequently than women. A feature of the X - linked inheritance is that fathers can not pass X - linked traits to their sons chromosome. In approximately one third of cases, Menkes syndrome is caused by new mutations in the gene atp7a. People with a new mutation have no history of the disease in his family.
Tests in IVAMI: in IVAMI perform detection of mutations associated with Menkes syndrome, by complete PCR amplification of exons ATP7A gene, and subsequent sequencing.
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).