What is osteogenesis imperfecta (OI)?
Osteogenesis imperfecta (OI) is a genetic skeletal disorder characterized by abnormally fragile bones. It is often called "brittle bone disease" and affects individuals throughout their lifetime. OI individuals may have blue sclerae, a bluish "tint" in the whites of their eyes, a history of fractures and dental changes in some individuals. OI occurs because of changes in genes (mutations) that affect connective tissues and bone cell function.
What happens to someone with OI?
Individuals with OI may experience fractures in varying severity and circumstances, typically from childhood through puberty and then in later life. People who have OI have been found to have other medical characteristics and issues as they mature, including:
- Muscle or bone pain
- Hearing loss
- Changes in eye tissues
- Dentinogenesis imperfecta (brittle teeth)
- Short stature
- Pulmonary/respiratory issues
- Cardiac issues
- Kidney/renal issues
What are the types of OI?
OI is classified into various types based upon symptoms, but are generally referred to as "mild" or "severe". To date, there are several types of classifications. More recent classification has been based on genetic findings. In all there are 17 types of OI, based on mutation information, however the majority of OI are type I through type IV, which are caused by mutations in COL1A1 and COL1A2
- Type I: mildest form, about 60% of all OI cases, blue sclerae, looks "normal".
- Type II: most severe form; infants born tend to survive about 2-3 weeks because of severe respiratory or cardiac complications.
- Type III: most severe form among children who survive neonatal period, blue sclerae, extremely short stature, triangular faces, bone deformity and limited ambulation.
- Type IV: moderately affected compared to Type III, significant scoliosis and bone deformity.
- Type V: Dislocation of the head of the radius in the forearm, large hyperplastic calluses after fracture, calcification of interosseous membrane in the forearm.
- Type VI through Type XVII: Clinically resembling moderately severe to severe forms of OI and inherited in an autosomal recessive manner.
For additional detail on each of the above, visit the Osteogenesis Imperfecta (OI) Foundation.
What can I do about OI?
There is currently no "cure" for OI; however, there are ways to manage OI. Despite the obstacles they face, many individuals with OI are able to enjoy productive and fulfilling lives well into their adult years. Current ways to treat or manage OI include:
- Physical therapy and safe exercise, including swimming
- Casts, splints or wraps for broken bones
- Braces to support legs, ankles, knees and wrists, as needed
- Orthopedic surgery, often including implanting rods to support the long bones in arms or legs
- Medications (bisphosphonates, anabolic agents, calcium, vitamin D) to strengthen bones
- Mobility aids such as canes, walkers, or wheelchairs and other equipment or aids for independence may be needed to compensate for weakness or short stature.