Researchers identify 5 new genetic variations in total of 11 thought to be important in Parkinson’s Disease risk

Parkinson’s Disease (PD) is a common neurodegenerative disease, affecting >2% of people over the age of 75 years. Most individuals develop the disorder in their 60’s and 70’s.   In the last decade it has become clear that there is a substantial genetic component to the disorder. 

Rare families have been identified across the world in whom PD is a result of a mutation in a single gene that leads to developing the disease. These families often have multiple affected individuals with PD.  Collectively, such families account for only about 5% of people diagnosed with Parkinson’s, but can tell us a great deal about how PD develops.

Most individuals with PD do not have a genetic mutation of this type, although it is believed they have an inherited susceptibility to the disease. Susceptibility (or risk) of developing PD is also thought to be genetically determined, but is likely to be due to a large number of changes across multiple genes each exerting a weak effect. This risk then possibly interacts with environmental factors to determine the overall probability of developing Parkinson’s disease.

There have been several studies, called genome-wide association studies, published in the last few years, designed to look at genetic differences between individuals with PD and those without. Genome-wide association studies have already identified changes in 6 genes that increase an individual’s risk of developing PD.

In this recent paper, published in the Lancet, Parkinson’s disease researchers from 6 different countries, led by the team at the Institute of Neurology, Professor Nick Wood, Department of Molecular Neuroscience, pooled 5 genome-wide association studies in which more than 5,000 individuals with PD were studied and compared with 12,000 healthy individuals. The results were then analyzed collectively, confirming the role of the 6 genes previously identified, as well as revealing a further 5 new genes likely to be important in the development of Parkinson’s Disease.

The authors of this paper now intend to study these genes in greater detail to  determine how changes in these genes influence the development of PD. 

reference >> The Lancet, Early Online Publication, 2 February 2011
doi:10.1016/S0140-6736(10)62345-8
Imputation of sequence variants for identification of genetic risks for Parkinson's disease: a meta-analysis of genome-wide association studies

International Parkinson Disease Genomics Consortium‡

read more >> The Telegraph