Parkinson's study: 'There is no definitive test'
16 April 2012 Last updated at 09:14 BST
Researchers are to conduct the world's biggest study into the causes of Parkinson's disease, a brain condition that affects almost 130,000 people in the UK.
They are hoping to find better ways of both diagnosing and treating the disease.
Charity Parkinson's UK is looking for 3,000 volunteers with the condition - and their siblings - to take part in the study.
Study director Dr Kieran Breen spoke to BBC Breakfast to explain more. He was joined by Paul Wilson, who was diagnosed with Parkinson's in 2006.