15 Oct 07

Oxford scientists are to lead in the world’s first search of the human genome for genetic risk factors for osteoarthritis.

The consortium of experts, led by principal investigator Dr John Loughlin, a geneticist from the Nuffield Department for Orthopaedic Surgery, will run a definitive genome-wide association study of osteoarthritis susceptibility called arcOGEN; the largest study of its kind ever undertaken.

The study will involve screening the DNA of 8,000 people suffering from osteoarthritis of the hip and knee and 6,000 healthy people to compare the differences. The two-year study will be funded by a grant of £2.2m – the largest single grant ever awarded by the medical research charity.

The aim of the arcOGEN study is to identify the genetic changes, known as polymorphisms, that increase the risk of people developing osteoarthritis. The charity expects that this could lead to several potential breakthroughs such as genetic tests becoming available to predict who is likely to develop osteoarthritis, particularly at a young age, and how severely. Ultimately it could lead to new drugs that could slow down disease progression and even prevent osteoarthritis occurring.

Osteoarthritis (OA) is the most common type of arthritis, affecting more than two million older people in the UK, causing pain and stiffness as the cartilage at the ends of bones wears away. It can affect any joints but involvement of the knee and hip is the number one cause of mobility problems in the elderly population. Despite its high prevalence there is no effective drug treatment to control the progression of osteoarthritis, and currently available painkillers carry a high risk of side effects.

Wrongly thought of as an inevitable consequence of ageing, osteoarthritis is a disease in its own right but the reasons why some people do, and some do not develop the disorder are unclear. The arcOGEN team hope to find between ten and 20 of the genes that could have a strong to moderate risk for osteoarthritis, although there may be many more. Human DNA contains about 30,000 genes.

Dr Loughlin said: ‘Osteoarthritis is an extremely debilitating disease characterised by joint pain and reduced mobility, and is the biggest cause of disability in older people bar none. Genetic factors play a major role in the development of OA and identifying them will help us to understand why the disease occurs and will assist in the development of new treatments by identifying new molecular targets. We have brought together all the major OA genetics research groups within the UK and experts in human genetics to enable us to perform the definitive search of the human genome for OA genetic risk factors.’

For more information, go to to www.arc.org.uk