Distal myopathy related CAV3 (CAV3-related distal myopathy) - Gen CAV3.

The distal CAV3 related myopathy is a form of distal myopathy, a group of diseases characterized by weakness and loss of function affects the distal, such as the muscles of the hands and feet muscles disorders. In general, the signs and symptoms of the disease become evident in adulthood and include atrophy and weakness of the small muscles of the hands and feet. A lump or other sudden impact on muscles, especially in the muscles of the forearms, can cause rapid contraction. These contractions may take up to 30 seconds and can be painful. In addition, those affected may have hypertrophy of the calf muscles. This disease does not affect the proximal muscles such as the thighs and upper arms muscles.

The distal CAV3 related myopathy is part of a group of disorders called caveolinopathies, due to mutations in the gene CAV3. The CAV3 gene, located on the short arm of chromosome 3 (3p25), encodes a protein called caveolin-3, located in the muscle cells surrounding the membrane. This protein is the major component of caveolae. Within the caveolae, caveolin-3 protein acts as a scaffold for organizing other molecules that are important for cell signaling and maintaining celular.Estas structure molecules, including proteins that form the sodium channels in the cells. Sodium channels play a key role in the ability of a cell to generate and transmit electrical signals. In cardiac muscle, sodium channels are involved in maintaining normal heart rhythm. Caveolin-3 protein can also help to regulate calcium concentrations in the muscle cell, controlling muscle contraction and relaxation.

They have identified at least two mutations in the gene CAV3 in people with distal myopathy. These mutations result in a deficiency of caveolin-3 in the muscle cell membrane and a reduction in the number of caveolae. It is believed that caveolae deficiency affects the structural integrity of the muscle cells, interfering with cell signaling and causes apoptosis. The consequent degeneration of muscle tissue resulting in signs and symptoms of myopathy related distal CAV3.

Besides the distal myopathy related CAV3, mutations in the gene may lead CAV3 other caveolinopathies including girdle muscular dystrophy, muscle ripple disease, hyperCKemia isolated, and a heart condition called hypertrophic cardiomyopathy. They have identified several mutations in the gene that cause CAV3 caveolinopathies different in different individuals. It is not clear why a single gene mutation can cause CAV3 different patterns of signs and symptoms, even within the same family.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to cause the alteration. In most cases, an affected person has a parent with distal myopathy related to CAV3 or other caveolinopatía. Some cases, though rare, are caused by new mutations in the gene and occur in people with no history of caveolinopathies in your family.

Tests in IVAMI: in IVAMI perform detection of mutations associated with distal myopathy related CAV3 by the complete PCR amplification of exons CAV3 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).