Osteogenesis imperfecta, often called “brittle bone disease”, is a genetic anomaly that makes bones particularly fragile from childhood. If it is incurable, treatments can improve the lives of those affected.
Definition: what is brittle bone disease?
Brittle bone disease or osteogenesis imperfecta is a rare disease of genetic originwhich results in repeated fractures and which affects especially young children. This disease results from a abnormality in chromosomes 7 or 17. “Some benign forms will only be discovered in adulthood following a fracture. The earlier this phenomenon begins in childhood, the more the disease is likely to be severe with significant consequences. In the most severe forms, children or young adults may have had several dozen or even a hundred fracturess”, comments Professor Pierre Lafforgue, head of the rheumatology department at Sainte-Marguerite hospital in Marseille.
What is another name for brittle bone disease?
Brittle bone disease is also called osteogenesis imperfecta.
What are the symptoms of brittle bone disease?
Osteogenesis imperfecta is manifested by a bone fragility, this one causing recurrent fractures, the first of which usually occurs in young children when learning to walk. They mainly affect the long bones of the lower limbs, the fracture of the femur being one of the most common. Brittle bone disease can also cause flat bone fractures (ribs and vertebrae). The frequency of fractures tends to decrease over time, especially in women through the production of estrogen. Other symptoms may be associated with osteogenesis imperfecta, but not all of them appear systematically: bone, cranial or spinal deformities, short stature, bluish whites of the eyes, deafness, hyperlaxity (ligaments more fragile and more elastic than normal), and dentinogenesis imperfecta (prematurely worn teeth).
Brittle bone disease is caused by a defect in the production of a bone component: the collagen. This is an anomaly of genetic origin, which can manifest in different forms depending on the affected genes and mutations. It is usually passed down from generation to generation, but it is not contagious.
“The disease can be confused with child abuse”
The diagnosis is essentially clinical, genetic testing is rarely needed to confirm it. “It is done by simple observation that fractures occur for no particular reason. Spontaneous fractures, or fractures that occur following minor trauma such as having made a false step or having fallen from its height, will make a search for bone fragility. If this happens in childhood, it should immediately think of osteogenesis imperfecta. At this time of life, the disease can be mistaken for child abuse. It is important not to be mistaken because it is tragic to accuse a family of abuse when they are already traumatized by what is happening.“, says the rheumatologist.
What are the consequences of brittle bone disease?
The consequences of brittle bone disease essentially depend on its severity. “Some people can lead a perfectly normal life when fractures are going to be detected, and heal within normal timeframes. Conversely, other people have so many fractures since childhood that they end up with skeletal deformities, in which case the impact is very important. This handicap forces them to have to move around in a wheelchair and need help with daily living. Most of the time it is compatible with a normal life“, explains Professor Pierre Lafforgue.
What is the treatment for brittle bone disease?
There is no no curative treatment to cure brittle bone disease, but appropriate support helps relieve symptoms. Support is mainly based on re-education, to be followed throughout life to acquire autonomy and mobility. It can be supplemented by respiratory physiotherapy exercises and by balneotherapy sessions. Medical treatments can also be offered to relieve pain. Other symptoms are treated on a case-by-case basis depending on the form of the disease. Dentinogenesis imperfecta must be treated quickly, with crown or implant placement. “We must also avoid making matters worse by ensuring that the vitamin D and calcium intake are sufficient not to add a deficiency to this state“, adds the expert.
What is the life expectancy with brittle bone disease?
“Life expectancy is not so reduced, except in severe forms, because the deformation of the skeleton can lead to complications on organs“, informs the rheumatologist. Brittle bone disease is classified into 4 types according to its severity and symptoms. Type 1 designates the most frequent forms causing few fractures, with a normal size. Type 2 corresponds to lethal forms: children with this form of osteogenesis imperfecta usually die after birth Type 3 is characterized by severe but non-lethal forms, and type 4 by symptoms of intermediate severity (between type 1 and type 3).
Thanks to Pr Pierre Lafforgue, head of the rheumatology department at Sainte-Marguerite hospital in Marseille.