Osteogenesis Imperfecta: Symptoms, Causes & Treatment

Osteogenesis imperfecta is a rare bone disease that makes bones more fragile. This can lead to frequent fractures and symptoms such as short stature, scoliosis, or weak teeth.

This condition is also known as “brittle bone disease.” It is caused by genetic mutations that affect the production of type 1 collagen, which helps strengthen the bones and joints.

Treatment for osteogenesis imperfecta is usually guided by a pediatrician, orthopedist, or specialist care team. Treatment may include physical therapy or medication to improve quality of life and help reduce the risk and frequency of fractures.

Osteogenesis imperfecta symptoms

The main symptoms of osteogenesis imperfecta are:

• Frequent bone fractures

• Frequent joint dislocations or ligament sprains

• Weak teeth

• Abnormal curvature of the spine (scoliosis)

• Hearing loss

• Breathing problems

• Short stature

In addition, osteogenesis imperfecta can cause blue sclera, which is a bluish color in the white part of the eyes.

Children with osteogenesis imperfecta may also have heart defects, which can be serious and, in some cases, life-threatening.

Confirming a diagnosis

In some cases, osteogenesis imperfecta can be diagnosed during pregnancy on a prenatal ultrasound. If needed, an OB-GYN may order tests such as amniocentesis, chorionic villus sampling (CVS), or genetic testing to confirm the diagnosis.

After birth, the diagnosis can be made by a neonatologist, pediatrician, or pediatric orthopedist. Diagnosis is based on symptoms, family history, imaging tests, and genetic testing, and may also include blood or urine tests to rule out other conditions.

Main types

The main types of osteogenesis imperfecta are:

1. Osteogenesis imperfecta type I

Osteogenesis imperfecta type I is the most common and mildest form of the disease. It is caused by a 50% reduction in type 1 collagen production.

This type causes little to no bone deformity and mild growth delay in children. However, the bones are fragile and can fracture easily.

Osteogenesis imperfecta type I can be subclassified as type IA, which is characterized by normal teeth, or type IB or IC, which involves changes in the teeth known as dentinogenesis imperfecta.

2. Osteogenesis imperfecta type II

Osteogenesis imperfecta type II is the most severe type of the disease and causes changes in collagen quality.

This type causes the fetus to have fractures inside the uterus, leading to miscarriage in most cases.

In addition, osteogenesis imperfecta type II can cause severe bone fragility, delayed skull bone formation, and blue sclera. This severe form of the disease can result in perinatal death.

3. Osteogenesis imperfecta type III

Osteogenesis imperfecta type III causes changes in the quantity and quality of type 1 collagen.

People with this type usually do not grow enough, have spinal deformities, and may have a bluish color in the whites of the eyes.

In addition, this type of osteogenesis imperfecta causes severe deformity of the long bones, bowed legs, difficulty moving around, and moderate to severe bone fragility.

4. Osteogenesis imperfecta type IV

Osteogenesis imperfecta type IV is also caused by changes in the quantity and quality of type 1 collagen, but it is more severe than type I.

This type of osteogenesis imperfecta is characterized by moderate to severe growth delay and bone fragility, as well as deformity of the spine and long bones.

Possible causes

Osteogenesis imperfecta is caused by genetic changes in the COL1A1 or COL1A2 genes. These changes affect the production or processing of type 1 collagen.

Type 1 collagen is the most abundant type of collagen in the body. It is part of the structure of connective tissues, such as bones, cartilage, the cornea, and ligaments.

Other genes that may also be altered and cause osteogenesis imperfecta include IFITM5, SERPINF1, LEPRE1, and PPIB.

Treatment options

Treatment for osteogenesis imperfecta should be done under the guidance of a pediatrician or orthopedist and aims to strengthen the bones and muscles.

According to the Eunice Kennedy Shriver National Institute of Child Health and Human Development, treatment for osteogenesis imperfecta is designed to prevent or control symptoms and support quality of life.

The main treatments for osteogenesis imperfecta are:

1. Physical therapy

Physical therapy for osteogenesis imperfecta may be recommended to help strengthen the muscles. Stronger muscles help support the bones, reducing the risk of fractures, dislocations, or sprains.

Physical therapy should be done with a physical therapist, who may recommend low-impact exercises such as hydrotherapy.

2. Medication

Medication for osteogenesis imperfecta may be recommended to help make the bones stronger and reduce the risk of fractures.

The main medications are bisphosphonates, such as pamidronate or alendronate, for example.

Treatment doses may need to be adjusted over time, so regular follow-up appointments with the doctor are important.

3. Immobilization or surgery

When fractures occur, the doctor may immobilize the bone with a cast or recommend surgery. Surgery may be needed, especially in cases of multiple fractures or fractures that take a long time to heal.

Fractures are treated in a similar way as they are in people without osteogenesis imperfecta. However, the time spent immobilized, such as in a cast, is usually shorter.

Important precautions

Some precautions for caring for children with osteogenesis imperfecta include:

• Avoid lifting the child by the armpits. Support the child’s weight with one hand under the buttocks and the other behind the neck and shoulders.

• Do not pull the child by an arm or leg.

• Choose a car seat with soft padding that allows the child to be taken out and placed in it with little effort.

Some children with osteogenesis imperfecta may be able to do light exercise, such as swimming, which can help lower the risk of fractures.

However, children should only exercise with a doctor’s approval and supervision from a physical therapist.