Espondiloperiférica dysplasia (Spondyloperipheral dysplasia) - Gen COL2A1.
The espondiloperiférica dysplasia is a disease affecting bone growth and characterized by platyspondyly and brachydactyly. Other skeletal abnormalities associated include short stature, long bones of the arms and shorter legs, lordosis and clubfoot. In addition, some affected individuals have myopia, hearing loss and intellectual disability.
This disease is due to mutations in the COL2A1 gene, located on the long arm of chromosome 12 (12q13.11). This gene encodes a component of collagen type II, called the pro-alpha1 (II) chain. This type of collagen is found primarily in the vitreous and cartilage. Most cartilage is later converted to bone. Collagen type II is essential for normal bone development and other connective tissues that form the support frame body. Collagen type II is also part of the vitreous, the inner ear, and the nucleus pulposus.
They have identified at least 4 COL2A1 gene mutations in people with espondiloperiférica dysplasia. All COL2A1 gene mutations associated with the disease occur in a region of the pro-alpha1 (II) called C-propeptide domain chain. C-propeptide domain is necessary for pro-alpha1 chain (II) are joined together to form type II collagen. Mutations leading to abnormally encoding pro-alpha1 short chain (II) that can not be incorporated into the fibers of type II collagen. As a result, the cells produce a reduced amount of type II collagen. Instead of forming collagen molecules, pro-alpha1 (II) chains abnormal accumulate in chondrocytes. These changes alter the normal development of bones, resulting in skeletal abnormalities that occur in the espondiloperiférica dysplasia.
This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to express the alteration.
Tests in IVAMI: in IVAMI perform detection of mutations associated with espondiloperiférica dysplasia, by complete PCR amplification of exons COL2A1 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).