Osteogenesis imperfecta: what it is, types and treatment

Imperfect osteogenesis, also known as glass bone disease, is a very rare genetic disease that causes a person to have deformed, short and more fragile bones, being susceptible to constant fractures.

This fragility appears to be due to a genetic defect that affects the production of type 1 collagen, which is naturally produced by osteoblasts and helps to strengthen bones and joints. Thus, the person who has osteogenesis imperfecta is born with the condition, and may present cases of frequent fractures in childhood, for example.

Although osteogenesis imperfecta has not yet been cured, there are some treatments that help improve the person's quality of life, reducing the risk and frequency of fractures.

Main types

According to Sillence's classification, there are 4 types of osteogenesis imperfecta, which include:

• Type I: it is the most common and the lightest form of the disease, causing little or no deformation of the bones. However, the bones are fragile and can fracture easily; Type II: is the most serious type of disease that causes the fetus to fracture inside the mother's uterus, leading to abortion in most cases; Type III: people with this type, normally, do not grow enough, present deformations in the spine and the whites of the eyes can present gray color; Type IV: it is a moderate type of the disease, in which there are slight deformations in the bones, but there is no color change in the white part of the eyes.

In most cases, osteogenesis imperfecta passes on to the children, but the symptoms and severity of the disease may be different, since the type of the disease can change from parents to children.

What causes osteogenesis imperfecta

Glass bone disease arises due to a genetic alteration in the gene responsible for producing type 1 collagen, the main protein used to create strong bones.

Because it is a genetic alteration, osteogenesis imperfecta can pass from parents to children, but it can also appear without other cases in the family, due to mutations during pregnancy, for example.

Possible symptoms

In addition to causing changes in bone formation, people who have osteogenesis imperfecta may also have other symptoms such as:

• Looser joints; Weak teeth; Bluish discoloration of the white of the eyes; Abnormal curvature of the spine (scoliosis); Hearing loss; Frequent respiratory problems; Short stature; Inguinal and umbilical hernias; Alteration of the heart valves.

In addition, in children with osteogenesis imperfecta, heart defects can also be diagnosed, which can end up being life-threatening.

How to confirm the diagnosis

The diagnosis of osteogenesis imperfecta can, in some cases, be made during pregnancy, as long as there is a high risk of the baby being born with the condition. In these cases, a sample is taken from the umbilical cord where the collagen produced by fetal cells between 10 and 12 weeks of gestation is analyzed. Another less invasive way is to do ultrasound to identify bone fractures.

After birth, the diagnosis can be made by the pediatrician or by a pediatric orthopedist, through the observation of symptoms, family history or through tests such as X-rays, genetic tests and biochemical blood tests.

What are the treatment options

There is no specific treatment for osteogenesis imperfecta and, therefore, it is important to have guidance from an orthopedist. Usually bisphosphonate drugs are used to help make bones stronger and reduce the risk of fractures. However, it is extremely important that this type of treatment is constantly evaluated by the doctor, as it may be necessary to adjust the treatment doses over time.

When fractures appear, the doctor may immobilize the bone with a cast or choose surgery, especially in the case of multiple fractures or that take a long time to heal. The treatment of fractures is similar to that of people who do not have the condition, but the immobilization period is usually shorter.

Physiotherapy for osteogenesis imperfecta can also be used in some cases to help strengthen the bones and muscles that support them, decreasing the risk of fractures.

How to care for a child with osteogenesis imperfecta

Some precautions to care for children with imperfect osteogenesis are:

• Avoid lifting the child by the armpits, supporting the weight with one hand under the butt and the other behind the neck and shoulders; Do not pull the child by an arm or leg; Select a safety seat with soft padding that allows the child to be removed and placed child with little effort.

Some children with imperfect osteogenesis may do some light exercise, such as swimming, as they help to reduce the risk of fractures. However, they should only do so after the doctor's guidance and under the supervision of a physical education teacher or a physical therapist.