Genes have bigger role in Parkinson's

Five new genes linked to the disease have been identified by scientists, leading to a rethink about the biological causes of the condition.

Until about 15 years ago Parkinson's was thought to be purely triggered by environmental factors.

Scientists now know around five per cent of people with Parkinson's inherit genes which increase the risk of developing the disease.

Parkinson's occurs when a brain chemistry imbalance disrupts motor nerve pathways, leading to symptoms of shaking, slowness of movement and rigidity.

An estimated 120,000 people in the UK suffer from the condition.

The new study was the largest in-depth investigation into the role of genes in Parkinson's ever conducted.

An international team of scientists from six countries scoured the DNA of 12,000 people with Parkinson's and more than 21,000 healthy participants looking for genetic differences between them.

Variations in a total of 11 genes were found to influence susceptibility to Parkinson's, including five previously not known to be linked to the disease.

The 20 per cent of patients with the highest number of risk variants were 2.5 times more likely to develop Parkinson's than the

20 per cent with the lowest number.

Professor Nick Wood, from the Institute of Neurology in London, who co-led the study, 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."

The research is published in The Lancet medical journal online.