New back pain gene identified in largest genetic study of its kind

(Press-News.org) Researchers at King's College London have for the first time identified a gene linked to age-related degeneration of the intervertebral discs in the spine, a common cause of lower back pain.

Costing the UK an estimated £7billion a year due to sickness leave and treatment costs, the causes of back pain are not yet fully understood. Until now, the genetic cause of lower back pain associated with lumbar disc degeneration (LDD) was unknown, but the largest study to date, published this week in the journal Annals of Rheumatic Diseases, has revealed an association with the PARK2 gene.

The researchers, funded by the Wellcome Trust and Arthritis Research UK, say more research into this surprising association needs to be carried out in order to fully understand how it is triggered, but this new finding could ultimately pave the way towards developing new treatments in the future.

LDD is a common age-related trait, with over a third of middle-aged women having at least one degenerate disc in the spine. Discs become dehydrated, lose height and the vertebrae next to the discs develop bony growths called osteophytes. These changes can cause or contribute to lower back pain. LDD is inherited in between 65 – 80 per cent of people with the condition, suggesting that genes play a key role.

Scientists compared MRI images of the spine in 4,600 individuals with genome-wide association data, which mapped the genes of all the volunteers. They identified that the gene PARK2 was implicated in people with degenerate discs and could affect the speed at which they deteriorate.

The researchers say the results show that the gene may be switched off in people with LDD. Although it is still unclear how this might happen, it is thought that environmental factors, such as lifestyle and diet, could trigger this switch by making changes known as epigenetic modifications to the gene.

Dr Frances Williams, Senior Lecturer from the Department of Twin Research and Genetic Epidemiology at King's College London, said: "Back pain can have a serious impact on people's lives and is one of the most common causes of sickness leave, costing both the NHS and UK economy billions each year.

"We have performed, using data collected from around the world, the biggest genome-wide association analysis of lumbar disc degeneration (LDD). We know that people whose discs wear out are at increased risk of episodes of lower back pain, but normal human discs are hard to get hold of to study so until now our knowledge of normal human biology was incomplete.

"We have identified a gene called PARK2 as associated with LDD. We have shown that the gene may be switched off in people with the condition. "Further work by disc researchers to define the role of this gene will, we hope, shed light on one of most important causes of lower back pain. It is feasible that if we can build on this finding and improve our knowledge of the condition, we may one day be able to develop new, more effective treatments for back pain caused by this common condition."

### View the paper, 'Novel genetic variants associated with lumbar disc degeneration in northern Europeans'

Notes to editors:

King's College London

King's College London is one of the top 30 universities in the world (2011/12 QS World University Rankings), and the fourth oldest in England. A research-led university based in the heart of London, King's has nearly 23,500 students (of whom more than 9,000 are graduate students) from nearly 140 countries, and some 6,000 employees. King's is in the second phase of a £1 billion redevelopment programme which is transforming its estate. King's has an outstanding reputation for providing world-class teaching and cutting-edge research. In the 2008 Research Assessment Exercise for British universities, 23 departments were ranked in the top quartile of British universities; over half of our academic staff work in departments that are in the top 10 per cent in the UK in their field and can thus be classed as world leading. The College is in the top seven UK universities for research earnings and has an overall annual income of nearly £450 million. King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar. It is the largest centre for the education of healthcare professionals in Europe; no university has more Medical Research Council Centres. King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: www.kingshealthpartners.org. The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests. www.wellcome.ac.uk

Arthritis Research UK is the leading authority on arthritis in the UK, conducting scientific and medical research into all types of arthritis and musculoskeletal conditions. It is the UK's fourth largest medical research charity and the only charity solely committed to funding high quality research into the cause, treatment and cure of arthritis. For more information, visit www.arthritisresearchuk.org