Osteogenesis Imperfecta (Brittle Bone Disease)

Osteogenesis imperfecta, commonly known as brittle bone disease, is a disorder caused by a defect in collagen production. Collagen is an essential protein that helps hold the body structures together. This protein has many types, with type 1 collagen being the most abundant form in the body. Type 1 collagen is found in the structure of bones, the white part of the eye, ligaments, and teeth. In osteogenesis imperfecta, there is a defect in the production of type 1 collagen. You can follow the rest of the article for more information on other topics related to osteogenesis imperfecta.

What is Osteogenesis Imperfecta (Brittle Bone Disease)?

Osteogenesis imperfecta, commonly known as brittle bone disease, is a condition characterized by the easy breaking of bones. This disorder is present from birth and particularly affects children who have family members with the condition. The medical term for this disease, “osteogenesis imperfecta,” means poorly formed bone structure.

The clinical findings of osteogenesis imperfecta can range from moderate to severe. Most identified cases are moderate, where a few bones may break easily. Severe cases can present with complications such as hearing loss, heart failure, spinal problems, or permanent deformities.

The prevalence of this disorder in the general population is approximately 1 in 20,000, affecting both males and females equally.

What are the Causes of Osteogenesis Imperfecta?

Osteogenesis imperfecta arises from mutations in the genes responsible for collagen production in the body. This disorder can be inherited from a parent through faulty genes, or it can occur due to spontaneous mutations in the child independent of the parents. The majority of osteogenesis imperfecta cases result from dominant mutations passed from an affected mother or father. In a small percentage of cases, recessive mutations inherited from both parents can be identified.

What are the Symptoms of Osteogenesis Imperfecta?

Individuals with osteogenesis imperfecta have weak and brittle bones. Some patients may experience bone fractures only a few times throughout their lives, while others may develop hundreds of fractures. In some cases, fractures may occur even while the fetus is still in the womb.

Aside from bone fractures, the clinical severity of the disease can vary and may be accompanied by various symptoms. Some of these symptoms include:

• Deformed or bowed long bones
• Short stature
• Easy bruising
• Loose joints and muscles
• Blue, purple, or gray sclera (the white part of the eye)
• Triangular facial shape
• Barrel-shaped chest
• Spinal curvature
• Compressed vertebrae
• Crooked, misshapen, or discolored teeth
• Hearing problems
• Breathing difficulties
• Deformity of the hip joint

Who is Affected by Osteogenesis Imperfecta?

Osteogenesis imperfecta is a disorder resulting from a defect or problem in the gene responsible for type 1 collagen production. This defective gene is typically passed down through family members across generations; however, in some individuals, the disease can arise from newly developed genetic mutations.

Approximately 90% of individuals with osteogenesis imperfecta have mutations in the COL1A1 and COL1A2 genes responsible for type 1 collagen production. The COL1A1 mutation is more frequently observed. Generally, the body requires type 1 collagen to maintain structural integrity. Bone tissue, skin, and connective tissue are among the tissues that require the highest amounts of type 1 collagen.

How is Osteogenesis Imperfecta Diagnosed?

Osteogenesis imperfecta can be diagnosed using X-ray imaging. When doctors examine the patient’s direct radiographs, they may find evidence of both new and old fractures. In addition to radiological examinations, various laboratory tests can be conducted to assess the patient's collagen production and structure. In some necessary cases, a skin biopsy may be performed to examine collagen status.

In patients suspected of having osteogenesis imperfecta based on these tests, genetic examinations are carried out to identify any existing abnormalities, resulting in a diagnosis of osteogenesis imperfecta.

What are the Types of Osteogenesis Imperfecta?

To date, there are 19 subtypes of osteogenesis imperfecta that have been identified. The most common forms of the disease can be summarized as follows:

Type 1 Osteogenesis Imperfecta
Type 1 osteogenesis imperfecta is a moderate form of the disease. In type 1, bones can easily break after moderate to severe trauma. This condition particularly arises before puberty. Individuals with type 1 osteogenesis imperfecta do not produce enough collagen.

Type 2 Osteogenesis Imperfecta
Type 2 osteogenesis imperfecta is the most severe form of the disorder. It can often lead to the loss of the baby due to respiratory failure before or shortly after birth. Babies with this type of brittle bone disease begin to fracture while still in the womb. Infants with type 2 osteogenesis imperfecta have very severe bone deformities, underdeveloped lungs, and improperly formed collagen structures.

Type 3 Osteogenesis Imperfecta
Type 3 osteogenesis imperfecta is considered the most severe form for babies who manage to survive after birth. Individuals with this type of brittle bone disease face physical limitations throughout their lives.

Types 4, 5, and 6 Osteogenesis Imperfecta
Individuals with type 4 osteogenesis imperfecta can easily fracture their bones before puberty and sometimes even before birth. These individuals may also exhibit moderate bone deformities, along with abnormalities related to the spine and rib cage structure.

The clinical symptoms of types 5 and 6 osteogenesis imperfecta are similar to those of type 4. When the bones of individuals with type 5 osteogenesis imperfecta are examined under a microscope, they show a lattice-like structure. In the case of individuals with type 6, the bone appearance resembles a fishnet.

How is Osteogenesis Imperfecta Treated?

Currently, there is no treatment approach that can eliminate osteogenesis imperfecta. The primary goal of treatment planning for these patients is to prevent potential injuries and support bone health. It is vital for children born with osteogenesis imperfecta to have a nutrient-rich diet, engage in regular exercise, and maintain a healthy weight. In severe forms, assistive medical devices may be utilized to support the child’s mobility.

Surgical intervention for osteogenesis imperfecta varies depending on the severity of the disease and the age of the patient. In young children with multiple fractures, it is possible to perform surgical treatment for all fractures simultaneously without resorting to casting or splinting.

In addition to surgical fracture treatment, doctors may also prescribe bisphosphonates and calcium-containing preparations. This supportive treatment aims to strengthen the bones and reduce the likelihood of fractures.

How Can the Quality of Life for Patients with Osteogenesis Imperfecta be Improved?

Various interventions, based on the knowledge and recommendations of physicians, can enhance the quality of life for individuals with osteogenesis imperfecta:

• Establishing a healthy and balanced nutrition plan
• Achieving a healthy body weight to minimize stress on the bones
• Engaging in strengthening exercises such as swimming
• Avoiding habits that disrupt bone structure, such as caffeine consumption

It is quite normal for individuals with osteogenesis imperfecta to experience mental health issues. If you or someone around you with this condition shows signs of depression or anxiety disorders, it is advisable to seek support from healthcare institutions. Wishing you healthy days ahead.