Vitroretinocoroidopatía autosomal dominant (autosomal dominant vitreoretinochoroidopathy) - Gen BEST1.
Autosomal dominant vitroretinocoroidopatía (ADVIRC) is a disease that affects various parts of the eye, including the vitreous humor, retina and choroid. ADVIRC ocular abnormalities can lead to varying degrees of vision impairment, mild to full loss, although some people with the disease have normal vision.
Signs and symptoms of the disease vary, even among members of the same family. Many affected individuals have microcornea, where the cornea is abnormally small and curved. The area behind the cornea can also be abnormally small. In addition, affected individuals may develop glaucoma or cataracts. Some people have vitreous degeneration or choroid. A characteristic feature of ADVIRC, visible with a special eye exam, is hyperpigmentation on the retina. This feature can help doctors diagnose disease. Affected individuals may also have white spots on the retina.
This process is due to mutations in the BEST1 gene, located on the long arm of chromosome 11 (11q13). It is believed that the protein encoded from this gene, termed bestrophin-1, plays a critical role in normal vision. Bestrophin-1 is in the retinal pigment epithelium. This layer of cells supports and nourishes the retina and is implicated in the growth and development of the eye, maintaining the retina, and normal function of photoreceptors. Pigment epithelium of the retina, bestrophin-1 functions as a chloride channel carrying ions across the cell membrane.
They have identified at least four mutations in the BEST1 gene in individuals with autosomal dominant vitroretinocoroidopatía (ADVIRC). These mutations change the BEST1 gene nucleotides at altering the way in which the gene encodes bestrophin-1, which leads to coding versions of the protein in certain segments missing or have additional segments. It is unclear how these versions of bestrophin affect the transport of chloride ions or lead to eye abnormalities ADVIRC characteristics. It is likely that these abnormalities are related to defects in the retinal pigment epithelium and photoreceptor.
This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for the disease to be expressed. In most cases, an affected person has a parent with the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with autosomal dominant vitroretinocoroidopatía (ADVIRC), by complete PCR amplification of exons BEST1 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).