TYPES
There are several types of osteogenesis imperfecta. They vary in severity and other characteristics.
- Type I OI. The most common type of OI. The severity is mild with the bones susceptible to fracture and with loose joints and weak muscles. There is also a tendency to have toward spinal curvature, minimal bone deformity, brittle teeth, and hearing loss.
- Type II OI. The most severe form of OI that frequently leads to death shortly after birth. There are several fractures and bone deformities. The chest is narrowed, and the lungs are underdeveloped.
- Type III OI. Another severe type for those who survived the neonatal period. The bones can break easily, and the tendency to have bone deformities are common and may get worse as the child ages. Other characteristics include short stature, loose joints, poor muscle development, barrel-shaped rib cage, spinal curvature. There is also a tendency to have respiratory problems, brittle teeth, and hearing loss.
- Type IV OI. The severity varies from mild to severe. The bones can easily fracture with most becoming broken before puberty. Other characteristics include shorter stature, mild to moderate bone deformity, and barrel-shaped rib cage. There is also a tendency to have toward spinal curvature, brittle teeth, and hearing loss.
- Types I, II, III, and IV are the most common types. These are a result of a gene mutation in the type 1 collagen. Aside from the listed characteristics, these types share a common feature which is a blue or grey tint in the white of the eye and a triangular face.
There are other types of OI but are not common. This includes the Type V OI and Type VI OI which have the same characteristics with the Type IV OI however they are not a result of gene mutations of the type 1 collagen, and the leading cause is still unknown.
Type VII OI and Type VIII OI are types of brittle bone diseases that are inherited in a recessive manner. This means a defective gene was received from each parent. Type VII OI resembles some characteristics of Type IV OI while Type VIII OI resembles some features of the Type II OI or Type III OI.
SYMPTOMS
The symptoms and severity of the disease vary according to the type. It is a common symptom to have fragile bones which can be combined with:
- Bone deformities
- Broken bones
- Loose joints
- Weak teeth
- Bluish color in the white of the eye
- Bowed limbs
- An abnormal curve of the spine which can be kyphosis or scoliosis
- Early hearing loss
- Respiratory problems
- Heart problems