Vibratory urticaria (hives Vibratory) - Gen ADGRE2
Vibrational urticaria is a condition in which the skin is exposed to vibration, repetitive stretching or friction, resulting in allergy symptoms such as urticaria, angioedema, erythema and pruritus at the affected area. Other symptoms such as headaches, fatigue, weakness, blurred vision, a metallic taste in the mouth, facial flushing, and generalized swelling (especially of the face) can also occur during these episodes, especially if stimulation is intense or prolonged. The reaction occurs within minutes of stimulation and usually lasts up to an hour. Affected individuals may have multiple episodes per day.
This may be caused by a mutation in the gene ADGRE2 (ACCESSION G protein-coupled receptor E2), located on the short arm of chromosome 19 (19p13.1), encoding a protein found in several cell types the immune system, including mast cells. Mast cells, which are found in many body tissues, including skin, are important for normal function of the immune system protection. Also they play a role in allergic reactions that occur when the immune system overreacts to stimuli that are not harmful. However, the specific function of the ADGRE2 protein in mast cells is not well understood. The ADGRE2 protein consists of two subunits that interact: an alpha subunit that is in the outer surface of the cell and a beta subunit that spans the cell membrane and extends into the cell.
The mutation identified gene responsible ADGRE2 vibratory urticaria (Cys492Tyr or C492Y) changes the amino acid cysteine by amino acid tyrosine at position 492 of the sequence of the alpha subunit protein. The substitution alters the protein structure and causes less stable interaction between the two subunits. This fragile connection can be easier to break. Factors such as vibration, friction or stretching of the skin can alter the association between the subunits in mast cells. It has been suggested that once the subunits are disconnected, the beta subunit sends signals to mast cells to react and produce the symptoms of allergy skin that occur in the vibratory urticaria. Some people with vibratory urticaria have a mutation in the gene ADGRE2. These individuals affected, the cause of the disease is unknown.
Vibrational urticaria is inherited in an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to express the process. In most cases, an affected person has an affected parent.
Tests in IVAMI: in IVAMI perform detection of mutations associated with vibrational urticaria, by complete PCR amplification of exons ADGRE2 gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated card blood sample desiccated (IVAMI can mail the card to deposit the blood sample).