What is Osteogenesis Imperfecta?
Osteogenesis imperfecta, also called brittle bone disease, is a bone disorder that results in imperfectly formed bones which are fragile and break easily. It is a hereditary disease that usually runs in the family and affects young children.
What are the Causes of Osteogenesis Imperfecta/Brittle Bone Disease?
Osteogenesis imperfecta is caused due to a defect in the gene that produces type 1 collagen – a protein that is responsible for bone synthesis. The defective gene results in the formation of brittle bones that break easily under minor exertion or pressure.
What are the Different Types of Osteogenesis Imperfecta?
There may be up to eight different types of brittle bone disease due to variations in the gene. However, the four commonly recognized osteogenesis imperfecta (OI) are listed below :
Type 1 OI
In Type 1 OI, the body produces an inadequate amount of collagen resulting in mildly fragile bones. Children with type 1 OI typically develop bone fractures due to mild traumas. The teeth may also be affected, resulting in cavities and dental cracks. It is the most common and the mildest form of brittle bone disease.
Type 2 OI
In type 2 OI, the body either doesn’t produce enough collagen or produces sub-standard quality collagen resulting in bone deformities. Children born with this condition may have a narrowed chest, underdeveloped lungs, or broken/misshaped ribs. Babies with type 2 OI can die in the uterus or shortly after birth.
Type 2 OI is the most severe form of brittle bone disease and can be life-threatening.
Type 3 OI
Another severe form of brittle bone disease is the Type 3 OI. In this condition, your child’s body produces sufficient amounts of collagen, but of a poor quality. The child’s bones are susceptible to break even before birth. Bone deformities are common and may worsen as your child grows older.
Type 4 OI
Type 4 OI is a variable form of brittle bone disease with its symptoms range from mild to severe. Here too, your child’s body produces sufficient collagen but of an inferior quality. Children with type 4 OI are typically born with bowed legs which tends to minimize with age.
What are the Symptoms of Osteogenesis Imperfecta/Brittle Bone Disease?
Osteogenesis imperfecta may have a range of symptoms depending on its severity such as :
- Multiple fractures or broken bones
- Weak or loose joints
- Bone deformities such as :
- bowed legs and arms
- kyphosis : an abnormal outward curve of the upper spine
- scoliosis : or an abnormal lateral curve of the spine
- Bluish color in the white of the eye called the sclera
- Weak teeth
- Heart defects
- Early hearing loss
- Respiratory problems
How is Osteogenesis Imperfecta/Brittle Bone Disease Diagnosed?
The diagnosis of osteogenesis imperfecta is made through a thorough physical examination. An X-ray is routinely performed to view the internal abnormalities.
Sometimes, your doctor may also perform a skin punch biopsy. In this procedure, the doctor uses a sharp, hollow tube to remove a small sample of skin tissue to be viewed under a microscope. Other diagnostic tests may include :
- DNA test to identify the gene mutation
- Blood tests or urine tests to ensure that your child’s symptoms are not due to other conditions such as rickets
What are the Treatment Options for Osteogenesis Imperfecta/Brittle Bone Disease?
Osteogenesis imperfecta can be treated through a variety of methods that includes both a conservative approach and surgery. Your doctor will first begin your child’s treatment using a conservative approach which includes :
- Medications such as bisphosphonate to strengthen your child’s bones
- Physical therapy to improve your child’s mobility and muscle strength
- Low-intensity exercises such as swimming to build muscle strength and bone strength
- Walking aids
- Occupational therapy : This approach utilizes changes in the lifestyle or daily activities to help children manage their symptoms
Surgery is recommended for severe cases of osteogenesis imperfecta and those which fail to improve with conservative management.
Surgery for brittle bone disease or osteogenesis imperfecta surgery involves placement of rods in your child’s bones, usually the longer ones such as the thigh bone or femur, shinbone or tibia in the lower leg, and the humerus or long bone in your child’s arm from the shoulder to the elbow.
Care and Recovery for Osteogenesis Imperfecta/Brittle Bone Disease
Following surgery, your pediatric surgeon may give you specific instructions to be followed to help with your child’s healing and recovery.
A healthy diet rich in calcium and vitamin D, green leafy vegetables, fresh fruits, simple exercises, and physical therapy may be recommended for your child to improve their bone and muscle strength and range of motion.