Osteogenesis Imperfecta — Know It All!

All you need to know about Brittle bone disease.

Know your ailment well, so you can manage it better!!

Here we come with Osteogenesis Imperfecta today!

What is Osterogeneis Imperfecta?

Osteogenesis imperfecta is also known as :

• Vrolik Disease
• Fragilitas ossium
• Brittle Bone Disease

Osteogenesis imperfecta ( OI) is a genetic or heritable disease that easily breaks (breaks) in the bones, often without any obvious cause or injury. OI is also known as brittle bone disease, and with many medical complications, the symptoms can range from mild with just a few fractures to serious.

What happens in Osteogenesis imperfecta:

For most people, OI is caused by a change or defect in the genes which carry the instructions to make type I collagen. Type I collagen is a material that helps make them strong in bones. The gene defect causes the body to make collagen incorrectly or not to make enough, resulting in weak bones breaking more easily. The disease is not preventable.

Who gets the disease:

Although anyone may be born with OI, people with a family history of the disease are at higher risk of inheriting the disease through an abnormal gene transmitted from one or both parents. Genetic counsellors can help you understand OI’s genetics better.

Osteogenesis Imperfecta Types:

There are several types of OI, and various classifications are used depending on disease severity or the nature of the underlying gene defect. Type I is the most common and weakest form of OI. Type II is the severest OI form. Other forms of OI have symptoms which fall between Type I and Type II. An overview of the most commonly diagnosed forms follows. The remaining forms are rare and are still under review.

Type I

• Bones likely to break from mild to moderate trauma, with most broken bones occurring before puberty.
• No change or only slight changes to stature with aging.
• Loose joints and muscle weakness.
• Blue, purple, or gray tint to sclera (whites of the eyes).
• Triangular face.
• Curved spine with potential for compression of the vertebrae (spine bones) with aging.
• Mild or no bone deformity.
• Possible changes to the strength and color of teeth.
• Possible hearing loss.
• Normal collagen structure, but less than the normal amount.

Type II

• Frequently causes death at birth or shortly after, because of the inability to breathe.
• Numerous broken bones that develop before birth while the baby is still in the womb.
• Severe bone deformities.
• Very small stature.
• Underdeveloped lungs.
• Blue, purple, or gray tint to sclera.
• Improperly formed collagen.

Type III

• Most severe type among those who survive the neonatal period and usually results in the greatest number of physical disabilities.
• Easily broken bones with very little trauma over a lifetime. (Broken bones are often present at birth, and x-rays may reveal healed bone breaks that occurred before birth.)
• Small stature.
• Blue, purple, or gray tint to sclera.
• Loose joints.
• Poor muscle development in arms and legs.
• Barrel-shaped rib cage.
• Triangular face.
• Curved spine and compression or collapse of vertebrae.
• Possible lung problems that worsen with age.
• Often severe bone deformity.
• Possible changes to the strength and color of teeth.
• Possible hearing loss.
• Improperly formed collagen.

Type IV

• Bones break easily, sometimes before birth, with most broken bones occurring before puberty.
• Smaller than average stature.
• White or blue tint to sclera.
• Mild to moderate bone deformity.
• Vertebra compression or collapse.
• Barrel-shaped rib cage.
• Triangular face.
• Possible changes to the strength and color of teeth.
• Possible hearing loss.
• Improperly formed collagen.

Type V

• Clinically similar to Type IV OI in appearance and symptoms.
• A dense band seen on x-rays by the cartilage growth plate of the long bones.
• Unusually large calluses, called hypertrophic calluses, at the sites of fractures or surgical procedures. (A callus is an area of new bone that is laid down at the fracture site as part of the healing process.)
• Calcification of the membrane between the radius and ulna (the bones of the forearm), which results in restricted arm movement.
• Possible loose joints.
• White sclera.
• No changes to teeth.
• “Mesh-like” appearance to the bone when viewed under the microscope.
• Changes in the minerals in the bone.

Type VI

• Resembles Type IV OI in appearance and symptoms.
• Not always diagnosed at birth, and symptoms progress over time.
• “Fish-scale” appearance to the bone when viewed under the microscope.
• Curved spine.
• Diagnosed with bone biopsy or genetic studies.
• Changes in the minerals in the bone.

Type VII

• Resembles Type II and Type III OI in appearance and symptoms.
• White sclera.
• Small stature.
• Short humerus (upper arm bone) and short femur (upper leg bone).
• Possible smaller head size.
• Changes in the process of forming collagen.

Type VIII

• Resembles Type II and Type III OI in appearance and symptoms.
• White sclera.
• Small stature.
• Short humerus (upper arm bone) and short femur (upper leg bone).
• Possible smaller head size.
• Changes in the process of forming collagen.

What are the symptoms of Osteogenesis Imperfecta?

All patients with Osteogenesis imperfecta have weak, brittle bones. Some people who have OI may have only a few broken bones throughout their lives. Others may have hundreds of broken bones throughout their lives, including broken bones that occur prior to birth.

People with OI can show other symptoms, ranging from mild to severe, and varying from person to person. Including:

• Malformed or bowing of long bones.
• Small stature.
• Skin that bruises easily.
• Loose joints.
• Weak muscles.
• Whites of the eyes (sclera) that look blue, purple, or gray.
• A face shaped like a triangle.
• A rib cage shaped like a barrel.
• A curved spine.
• Collapse or compression of the vertebrae in the spine.
• Brittle, misshapen, or discolored teeth.
• Hearing loss.
• Breathing problems.
• A deformed hip joint in which the neck of the femur is bent downward, a condition called coxa vara.

What are the causes of Osteogenesis Imperfecta?

OI is caused by a mutation or alteration in a gene. Genes hold information which will decide which features your parents pass on to you. We’ve got two copies of most of our dna, one per parent.

People with OI have a gene that holds incorrect instructions about how to produce collagen, a material that strengthens bones. The gene causes the body not to generate enough collagen, or the collagen does not function properly. This leads to fast breaking of weak bones.

Most OI-patients inherit this gene from one parent. In other ways both parents must inherit a mutation in a gene. Parents do not need an OI to pass on the gene which causes it. At times the gene is not passed on by either parent. The gene instead stops functioning on its own properly until the child is born.

• Dominant OI:

Most OI-patients have a dominant form. That means they inherit one regular copy and one copy of the OI-causing gene. The abnormal gene copy is greater than the normal gene copy, or “dominant.” This is causing an OI for a human. An individual with a dominant mutation has a chance of passing on the condition to each of his or her children by 50 per cent (1 in 2). Any kids with the dominant OI type inherit a gene that causes a parent to have OI. While some are born with the dominant type of OI, but the condition has no family background and the mutation happens for the first time within the family in their genome.

• Recessive OI:

Some individuals with OI have a recessive form of the disorder. People with recessive OI have parents who have no OI but both of whom have an irregular gene causing the disease. When both parents possess the recessive gene for OI, the risk of having a child with the disease is 25 per cent (1 out of 4) per pregnancy. A individual with recessive OI, unaffected or asymptomatic siblings have a two-thirds risk (2 out of 3) of having an abnormal gene that causes OI, making them carriers of the disease. If one parent has OI due to a recessive mutation, all of their kids may have an odd gene that causes OI but doesn’t actually have OI.

How to diagnose Osteogenesis Imperfecta?

Doctors may diagnose OI by:

• Asking about family and medical history.
• Completing a physical exam.
• Ordering x-rays and bone density tests.

Furthermore, doctors can also diagnose OI and classify the type of OI with a genetic blood test that identifies the inherited gene alterations. In most people who do have it, these tests will detect OI. Often it can require further genetic testing. People with genetic testing may see a doctor or genetic counsellor to help them understand the outcome of the test.

What is the treatment for Osteogenesis Imperfecta?

OI doesn’t get healed. Depending on the form of OI, the aim of the treatment is to avoid or regulate symptoms, improve bone mass and muscle strength, and enhance an individual’s capacity to be independent. These therapies encompass:

Occupational or Physical Therapy:

People with OI may benefit from physical or occupational therapy, which can help the person:

• Build muscle strength; improve joint movement, mobility, and gross motor skills; and prevent broken bones.
• Learn how to avoid injuries.
• Safely perform activities of daily living.
• Recover from broken bones.

Therapists and doctors also may recommend swimming to condition and build strength.

Medications:

And there are no US-approved medicines. Food and Drug Administration may prescribe a therapy approved for a related condition for your doctor to treat OI. Can your doctor prescribe:

• Bone strengthening medicines approved to treat other bone diseases can help slow bone loss and reduce the frequency and seriousness of broken bones.
• Pain medicines to treat pain caused by broken bones and chronic bone pain.

Additionally, several drugs are currently being tested to help avoid complications in adults and children from or treat OI. Speak to your primary care physician or pediatrician about the use or involvement in trials of these medicines.

Bone Care:

An orthopedic surgeon can use plaster, splint, or brace to treat broken bones. People often need surgery to heal a broken bone.

Additionally, doctors do surgery to strengthen or fix curved or bent bones, including the spine. Many OI children undergo rodding surgery, in which a metal rod is inserted in a bone. Rodding surgery is done to support the bone and avoid fracturing of the bone. Some of these rods are “telescoping” and are flexible to lengthen when a child develops with OI.

Mobility Aids:

Using a mobility aid may help people safely perform daily activities and reduce injuries. These aids include:

• Walkers.
• Canes and crutches.
• Braces or prosthetics.
• Wheelchairs.

Oral and Dental Care:

Some people with OI have:

• Teeth that easily chip or break.
• Changes in tooth color and shape.
• Tooth decay.
• Small jaw size.
• Incorrect position of teeth.

Regular dental check-ups and care are important to prevent dental symptoms and improve bite, alignment and appearance of teeth. In addition, some people need to see:

• Oral-maxillofacial surgeon, who specializes in oral and jaw surgery.
• Orthodontist, who treats tooth alignment and jaw position.

Hearing:

Doctors recommend hearing tests starting in infancy, with regular testing throughout the life of the person. An audiologist who specialises in caring for people with OI is important to see. Treatment may include following:

• Hearing aids, small electronic devices worn outside the ear that make sound louder.
• Cochlear implants, small electronic devices that have two pieces, one outside behind the ear and another under the skin.
• Surgery called stapedectomy, when a surgeon places a prosthetic or artificial device into the middle ear, allowing sound waves to reach the inner ear.

How to Cope up:

Some practises will help OI people stay safe and avoid broken bones. They are:

• Follow a nutritious diet.
• Exercise as much as possible. Regular physical activity can help strengthen muscles and bones. Swimming and water therapy are common choices for people with OI because exercising in water has little risk for causing broken bones. Talk with your doctor or physical therapist to discuss appropriate and safe exercise.
• Keep a healthy weight. Being overweight increases the risk for many health problems, such as diabetes and heart disease. Extra weight also adds stress to the bones, which is especially unhealthy for people with OI.
• Don’t smoke, and avoid secondhand smoke, because smoking can also weaken bones.
• Do not drink a lot of alcohol or caffeine because they may weaken your bones.
• Seek counseling or talk to a health care professional if you feel depressed or anxious about OI and its symptoms.

References:

https://ghr.nlm.nih.gov/condition/osteogenesis-imperfecta

https://www.niams.nih.gov/health-topics/osteogenesis-imperfecta

By,

Gopala Krishna Varshith,

Content Developer & Editor,

Clipo.