Hope has been raised for osteoarthritis patients as scientists have uncovered dozens of genetic mutations that may be linked to the agonising condition.
In the largest study of its kind, researchers analysed the genomes of nearly 450,000 people, of which a fifth had the agonising condition.
The results – 52 new genes linked to osteoarthritis – have been branded a ‘major step forward’.
The discovery also means the known number of genes linked to the condition that strikes millions had more than doubled, to 86.
Figures estimate 10million people suffer with the degenerative joint disease in the UK and 30million in the US.
There is no cure for the condition, but the latest findings offer promise for the development of better treatment.
Scientists have discovered 52 genetic changes linked to osteoarthritis, described as a ‘major step forward’ in treatment
Scientists led by the Wellcome Sanger Institute, in Cambrdige, and pharmaceutical company GlaxoSmithKline analysed the genomes.
They also looked at gene activity in the tissue taken from 38 patients undergoing joint replacement surgery.
In order to discover which genes cause osteoarthritis, the team measured gene expression down to the protein level. The structure of proteins plays a crucial role understanding how genes are expressed.
By looking at which genes are switched on or off, the researchers can see which protein is being made.
The team studied many different types of osteoarthritis, including in knee and hip joints, of which are the most common.
They found 24 new signs for osteoarthritis at any site, 15 for hip osteoarthritis, seven for knee osteoarthritis, and six for osteoarthritis of the hip and/or knee.
Professor Eleftheria Zeggini, previously from the Wellcome Sanger Institute and now based at Helmholtz Zentrum München in Germany, told MailOnline that only a quarter of the genes thought to be linked to the condition have been identified to date.
WHAT ARE THE MOST EFFECTIVE TREATMENTS FOR KNEE OSTEOARTHRITIS?
The five most effective short-term pain-relievers for knee oestoarthritis (OA) are, in order:
1) Cortisone injections
3) Platelet-rich plasma (PRP) injections
Yet, naproxen is the best overall remedy to both improve joint function and minimise discomfort.
Hyaluronic acid (HA) injections appear to be relatively ineffective at relieving pain or boosting knee function in OA sufferers.
The research was carried out by the non-profit health system Dartmouth-Hitchcock, New England.
She said: ‘Although it is difficult to be accurate, we estimate that the proportion of heritability explained by the loci identified to date is 22.5 per cent for osteoarthritis at any site.
‘This means that bigger, better-powered studies will be necessary to elucidate the genetic component of disease in its entirety.’
Professor Zeggini added: ‘We have conducted the largest study of osteoarthritis to date, and found over 50 new genetic changes that increase the risk of developing osteoarthritis.
‘This is a major step forward in developing treatments to help the millions of people suffering from the disease.’
The disease is currently managed with pain relief medications and often patients end up needing joint replacement surgery, which has variable outcomes.
The findings, published in Nature Genetics, could help the development of new medicines and re-assessment of existing medicine.
Ten of the genes were highlighted as targets of existing drugs, which are either in clinical development or approved for use against osteoarthritis and other diseases.
For example LCL-161, a drug in clinical development for breast cancer, leukaemia and myeloma treatment, could be tested for osteoarthritis, too.
Dr Stephen Simpson, Director of Research at Versus Arthritis, who supported the arcOGEN study, said: ‘We know that the condition impacts people in different ways, meaning the treatment that works for one person doesn’t always work for someone else.
‘This study represents a hugely important milestone towards understanding the complexity of osteoarthritis and finding new treatments and we are delighted that our support for the arcOGEN study has helped deliver this.
‘In the long term, the research progresses us significantly on the journey to ending the pain, isolation and fatigue of those living with arthritis.’
Osteoarthritis affects 40 per cent of people over the age of 70, and is a major cause of pain, comorbidity, and mortality.