Genetic component to Parkinson’s disease discovered

By Dr. Ananya Mandal, MDFeb 3 2011

Dr Ananya Mandal, MD

Parkinson’s disease, a severely degenerative disease of the brain leading to tremors, muscle rigidity and finally immobility was until the 1990’s believed to be due to environmental factors, lifestyle and a person’s age. However, now scientists have discovered five more genes that influence its development. Scientists reveal that around 5% of people with Parkinson’s inherit genes which increase the risk of developing the disease. The study was published this Wednesday in The Lancet and has been hailed as “an exciting step forward” towards understanding the disease. PD affects about 120,000 people in Britain, or one in 500.

With this study a total 11 genes have been identified to be linked to PD. The study - the largest of its kind in the world - mapped and compared the DNA of 12,000 people with Parkinson’s and more than 21,000 without it. It noted that the fifth of people with the highest number of genetic “risk variants” were 2.5 times more likely to develop PD than those with the lowest number. Authors write, “This study provides evidence that common genetic variation plays an important part in the cause of Parkinson’s disease… We have confirmed a strong genetic component to Parkinson’s disease, which, until recently, was thought to be completely caused by environmental factors.”

One of the co-authors, Prof Nick Wood, of the University College London Institute for Neurology said, “Discovering five new genes is an exciting step forward and will help us understand more about why and how nerve cells die…These findings significantly add to the knowledge base of the increasingly complex picture of the molecules that can cause Parkinson’s.”

Dr Kieran Breen, director of research and development at the charity Parkinson’s UK, which helped fund the study, said, “In 2004 Parkinson’s UK funded researchers helped uncover changes in the LRRK2 gene…This is one of the most important genes involved in Parkinson’s and studies are looking at whether this may be a target for new drugs…In the same way, we hope that the results from this new study will lead to similar advances and help us to move closer towards better treatments, or even a cure for Parkinson’s.”