Osteogenesis Imperfecta: Why Do Bones Break Easily in Children?

Osteogenesis Imperfecta (OI), otherwise known as brittle bone disease, is a rare genetic bone disorder that manifests itself at birth. A child with this condition may have soft bones that easily break, bones without normal structure, or other issues. Furthermore, the severity of symptoms can range from mild to severe.

Different Types of Osteogenesis Imperfecta

Experts classify osteogenesis imperfecta into 19 distinct forms (Type I to XIX), which differ significantly. In particular, each type is determined by the type of inheritance and the exhibited symptoms. However, some types have the tendency to overlap with one another. Usually, it is the first four types that present themselves. 

Type I (Non-Deforming Osteogenesis Imperfecta with Blue Sclerae)

The first type is the mildest and most common kind of osteogenesis imperfecta. Type I affects roughly half of all affected children. It does not involve many fractures or deformities, however, children falling under this category may develop or have:

• Brittle bones
• Their first fracture early in childhood (they may get more as they get older)
• Scoliosis and other occasional spinal issues
• Blue sclera
• Hearing problems as they get older

Type II (Perinatally Lethal Osteogenesis Imperfecta)

Type II is the most severe type of brittle bone disease. Babies born with type II frequently are unable to breathe, thus they may eventually die at a young age. Children may show the following signs and symptoms:

Type III (Progressively Deforming Osteogenesis Imperfecta)

With type III, broken bones and severe physical disabilities are common in newborns. Following the different type considerations, this is the most severe wherein babies do not die as newborns. 

Each baby may have a unique set of symptoms but the common ones are:

• Extremely brittle bones
• Fractures prior to or at birth and other fractures throughout life
• Bone deformity (easily bending out of shape)
• Very short stature
• Barrel-shaped ribcages
• Scoliosis
• Breathing difficulties (which can lead to possible respiratory problems)
• Hearing difficulties 
• Brittle teeth
• Triangular face 

Type IV (Common Variable Osteogenesis Imperfecta with Normal Sclerae)

Bones are prone to breaking. Typically, the first bone break in a child of this type occurs before puberty.  The symptoms range from mild to severe.

At birth, a baby with type IV osteogenesis imperfecta may be diagnosed. He or she would not have any broken bones until learning how to crawl or walk. 

Children who suffer from this type of osteogenesis imperfecta may have:

• Varying degrees of bone fragility
• Serious bone deformities
• Short stature
• Frequent fractures (which may lessen after puberty)
• Spinal curvatures
• Brittle teeth
• Normal or near-normal colored sclera
• Breathing difficulties
• Hearing difficulties (possible hearing loss)

What Causes Osteogenesis Imperfecta in Children?

A gene mutation causes osteogenesis imperfecta. This mutation can be sporadic (happening at random), or a child can acquire the gene from either or both parents. However, there are parents who are carriers of the OI-causing gene. Being a carrier implies that one may not have the disease but can pass it on to their children.

Moreover, due to lack of type I collagen, babies born with OI have difficulty making connective tissue. Collagen is primarily present in bones, ligaments, and teeth, which contributes to bone strength. The body may not produce enough collagen as a result of the gene mutation, and bones may weaken.

How To Diagnose and Treat Osteogenesis Imperfecta in Children

X-rays, DNA tests, blood or urine tests, and even biochemical testing help diagnose brittle bone disease in children. In severe cases, prenatal testing, such as an ultrasound, can identify broken bones and other bone deformities before a baby is born. 

Unfortunately, osteogenesis imperfecta is incurable. However, therapy (both physical and occupational), mobility aids, medicine, and surgery each contribute to treat a child’s specific symptoms. The goal is to avoid fractures, treat them properly when they occur, maintain movement and function, as well as enhance bones and muscles.

Key Takeaway

Managing osteogenesis imperfecta puts focus on preventing or minimizing deformities as well as maximizing the child’s functional ability. Hence, modifying daily activities can reduce the risk of fractures. 

Learn more about Child Health here.