Osteogenesis imperfecta - congenital disorder characterized by fragile bones that have a tendency to increased fragility. People with osteogenesis imperfecta are born with defects in the connective tissue or collagen type I. deficiency In most cases, the disorder is caused by mutations in the genes COL1A1 and COL1A2. The disease occurs in one of 20,000 newborns.
The types of osteogenesis imperfecta
There are eight types of osteogenesis imperfecta.
Type I is the most common, it is different from the others in that the collagen has a normal quality properties, but is produced in insufficient quantities. Symptoms of type I osteogenesis imperfecta are:
- Brittle bones;
- The weakness of the joints;
- The slightly protruding eyes;
- Decreased muscle tone;
- Early hearing loss in some children;
- A slight curvature of the spine;
- The discoloration of the sclera (whites of the eyes), which usually gives them a blue-brown hue.
Symptoms osteogenesis imperfecta type II are:
- Lack of collagen;
- Respiratory problems due to underdeveloped lungs;
- short stature;
- Bone deformities.
Type II may be subdivided into groups A, B, C, which differ due radiographic long tubular bones and ribs.
In most cases, patients die within the first year of life due to respiratory failure or intracranial hemorrhage.
Osteogenesis imperfecta type III is characterized by the following symptoms:
- Collagen is produced in sufficient quantity, but not of sufficient quality;
- Light brittle bones, sometimes even at birth;
- Bone deformities;
- Possible problems with breathing;
- Short stature, spinal curvature, sometimes barrel-shaped chest;
- The weakness of the ligamentous apparatus of the joints;
- Weakness of muscle tone the arms and legs;
- Discoloration of sclera (whites of the eyes);
- Early hair loss.
Life expectancy may be normal, albeit with severe physical disabilities.
Type IV is characterized by symptoms of osteogenesis imperfecta:
- Collagen produced in sufficient quantities, but is not of sufficient quality;
- Bones break easily, especially before puberty;
- Short stature, spinal curvature and barrel-shaped chest;
- Mild to moderate bone deformities;
- Early hearing loss.
Type V osteogenesis imperfecta has the same clinical signs as type IV. Different appearance ethmoid bone, dislocation of the radial head and mixed hearing loss, leading to calcification of the membrane between the two bones of the forearm.
Type VI osteogenesis imperfecta has the same clinical features as Type IV, but has a unique histological findings of bone tissue. The causes of osteogenesis imperfecta type VI is the loss of function and gene mutation Serpin F1.
Cause osteogenesis imperfecta Type VII is a mutation of the protein of cartilage and osteogenesis imperfecta type VIII is a serious and fatal disorder which is associated with changes in protein containing leucine, and proline.
Treatment for osteogenesis imperfecta
The treatment of osteogenesis imperfecta does not exist, as this disease is a congenital (genetic). Treatment is aimed at improving the overall strength of the bone to prevent and halt their further destruction. Also used bisphosphonate therapy that increases bone mass, decreased bone pain and destruction. In severe cases, surgery is used and placed inside the bone pins.