Osteogenesis Imperfecta in Children

What is osteogenesis imperfecta in children?

Osteogenesis imperfecta (OI) is a rare inherited (genetic)bone disorder that is present at birth. It's also known as brittle bone disease. A child born with OI may have soft bones that break (fracture) easily, bones that are not formed normally, and other problems. Symptoms may range from mild to severe.

There are at least 8 different types of the disease. The types vary greatly, both within and between types. They are based on the type of inheritance (see below), and symptoms. These include findings on X-rays and other imaging tests. The OI types are as follows:

  • Type I. Mildest and most common type. About 50% of all affected children have this type. There are few fractures and deformities

  • Type II. Most severe type. A baby has very short arms and legs, a small chest, and soft skull. He or she may be born with fractured bones. He or she may also have a low birth weight and lungs that are not well developed. A baby with type II OI usually dies within weeks of birth

  • Type III. Most severe type in babies who don’t die as newborns. At birth, a baby may have slightly shorter arms and legs than normal and arm, leg, and rib fractures. A baby may also have a larger than normal head, a triangle-shaped face, a deformed chest and spine, and breathing and swallowing problems. These symptoms are different in each baby.

  • Type IV. Symptoms are between mild and severe. A baby with type IV may be diagnosed at birth. He or she may not have any fractures until crawling or walking. The bones of the arms and legs may not be straight. He or she may not grow normally.

  • Type V. Similar to type IV. Symptoms may be medium to severe. It is common to have enlarged thickened areas (hypertrophic calluses) in the areas where large bones are fractured

  • Type VI. Very rare. Symptoms are medium. Similar to type IV.

  • Type VII. May be like type IV or like type II. It's common to have shorter than normal height. Also common to have shorter than normal upper arm and thighbones. 

  • Type VIII. Similar to types II and III. Very soft bones and severe growth problems.

What causes osteogenesis imperfecta in a child?

OI is passed on through the genes. The different types are passed on in different ways. The gene may be inherited from one or both parents. Or the gene can be passed on from an unexplained change (spontaneous mutation) of a gene.

Most babies with OI have a defect of one of two genes. These genes help in forming collagen. Collagen is a main part of connective tissue that connects and supports the whole body, including the bones. Because of the defect, there is not enough collagen. Or the collagen is abnormal.

What are the symptoms of osteogenesis imperfecta in a child?

The symptoms of OI vary greatly within and between types. Symptoms of OI include:

  • Easily broken bones

  • Bone deformities, such as bowing of the legs

  • Discoloration of the white of the eye (sclera), may be blue, purple, or gray in color

  • A barrel-shaped chest

  • A curved spine

  • A triangle-shaped face

  • Loose joints

  • Muscle weakness

  • Skin that easily bruises

  • Hearing loss in early adulthood

  • Breathing problems

  • Soft, discolored teeth 

The symptoms of osteogenesis imperfecta may look like other medical conditions. Always see your child's healthcare provider for a diagnosis.

How is osteogenesis imperfecta diagnosed in a child?

Your baby's healthcare provider will ask questions about your baby's medical history, your family and pregnancy history, and your baby's current symptoms. He or she will examine your baby, looking for symptoms of OI. The milder forms of OI may be hard to diagnose in a baby.

Your baby's healthcare provider may refer you to specialists with experience in diagnosing and treating OI. For example, your baby may be referred to a specialist in genetic conditions (geneticist) or in bone disorders (orthopedist).

Your baby's healthcare provider or the specialists may recommend the following diagnostic tests:

  • X-rays. These may show many changes such as weak or deformed bones and fractures.

  • Lab tests. Blood, saliva, and skin may be checked. The tests may include gene testing.

  • DEXA (dual energy X-ray absorptiometry) scan. A scan of the bones to check for softening.

  • Bone biopsy. A sample of the hipbone is often checked. This test requires anesthesia.

How is osteogenesis imperfecta treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

The main goal of treatment is to prevent deformities and fractures. And, once your child gets older, to allow