The brittle bone diseases are a large group of conditions characterised by excessive fragility of the bones, present from childhood.

The most common cause of the disorder is osteogenesis imperfecta which is a group of conditions all caused by inherited defects of collagen (the protein responsible for the strength of the bone). The severity of the condition may vary. Some affected individuals have multiple fractures, in others the condition is difficult to diagnose.

It is conventional to describe four varieties of osteogenesis imperfecta. Type II usually causes such severe fractures that infants are stillborn or die in the first few weeks of life. Type III is severe but consistent with good survival although there may be markedly impaired growth. Types I and IV are milder conditions with good stature and relatively few fractures. Type I is characterised by distinctly blue/grey sclerae (whites of the eyes) which is not seen in Type IV. Associated problems may include lax joints, fragile teeth, excessive sweating and easy bruising.

Other less common causes of brittle bone disease include osteopetrosis hypophosphatasia, fibrous dysplasia (Albright Syndrome) and ideopathic juvenile osteoporosis. Additionally temporary brittle bone disease may cause fractures in the first year of life and improve later. This is still not well understood. Fracture in childhod may also be caused by rickets due to vitamin D deficiency.

Inheritance Patterns:   Type I and IV are usually autosomal dominant but new mutations often occur. There are a variety of genetic causes for type II and type III and skilled genetic counselling is necessary.

Pre-Natal Diagnosis:  Severe cases may be detected by ultrasound scanning. A DNA test may be available at eight weeks for some affected families where the family has already been studied. Genetic counselling is available for affected families.

Further information available from:

Brittle Bone Society,
30 Guthrie Street,
Dundee
DD1 5BS

Helpline Tel: 08000 282459 (Freephone)

(Also Tel: 01382 204446/7 and Fax: 01382 206771

e-mail: bbs@brittlebone.org

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The brittle bone society http://www.brittlebone.org is Registered charity 272100. It was formed in 1971 and offers:

• Advice, encouragement and practical help for affected individuals and their families.
• Information on sources of medical, orthopaedic and genetic advice.

Activities

• Local meetings and AGM held throughout the country
• Fundraising for specialised equipment not otherwise available
• Support research in various British Universities
• Two part time occupational therapists visit families throughout the UK

There are 800 members and they publish a newsletter three times a year