What Is Osteogenesis Imperfecta?
Osteogenesis imperfecta (OI) is a disease that causes weak bones that break easily. It is known as brittle bone disease. Sometimes the bones break for no known reason. OI can also cause many other problems such as weak muscles, brittle teeth, and hearing loss. About 20,000 to 50,000 people in the United States have OI.
OI is caused by one of several genes that aren’t working properly. Genes carry our hereditary (family) information. We each have two copies of most genes: one set from each parent. Genes are what make you look like your biological family.
Each of the genes that cause OI plays a role in how the body makes collagen. Collagen is a material in bones that helps make them strong. When these genes aren’t working properly, there isn’t enough collagen, or the collagen doesn’t work properly. This leads to weak bones that break easily.
Most children inherit the gene that doesn’t work properly from one parent. Some inherit it from both parents. In some cases, neither parent passes on this gene. Instead, the gene stops working properly soon after the child is conceived.
All people with osteogenesis imperfecta have brittle bones. OI can range from mild to severe and symptoms vary from person to person. Some of the symptoms that people with OI may have are:
- Malformed bones
- Short, small body
- Loose joints
- Muscle weakness
- Sclera (whites of the eyes) that look blue, purple, or gray
- Triangular face
- Barrel-shaped rib cage
- Curved spine
- Brittle teeth
- Hearing loss (often starting in 20s or 30s)
- Breathing problems
- Type 1 collagen that does not work well
- Not enough collagen.
There are 8 main types of osteogenesis imperfecta. People with types 2, 3, 7, and 8 tend to have severe symptoms. People with types 4, 5, and 6 tend to have more moderate symptoms. People with type 1 tend to have mild symptoms.