During the past decade it has become clear that genetic factors are important in determining whether an individual will develop Parkinson's disease. Several research groups are now trying to identify the genes that may increase an individual's risk of developing Parkinson's disease. This proposal seeks to bring together several large research groups in the United States and Europe who all have found evidence that there may be a gene on chromosome 5 that increases the risk for Parkinson's disease.
Together, these studies have already studied more than 700 sibling pairs affected with PD. This collaborative group will now focus their joint efforts on examining chromosome 5 to determine more definitively whether a gene on that chromosome might be important in Parkinson's disease susceptibility. To accomplish this goal, the collaborating researchers will study the same sequences of DNA from all the study participants. Then, genetic analyses will be performed to try to determine where on chromosome 5 the collaborative group should focus to find a gene that increases the risk of Parkinson's disease.
Dr. Foroud combined two large datasets (one from the U.S. and one from the U.K.) consisting of more than 1,200 DNA samples from PD-affected families in which more than one individual has PD. The datasets were used to confirm the findings of previous preliminary studies that a region on DNA chromosome 5 contains a gene variant that increases the risk of PD. Based on her analysis, it was impossible to confirm this hypothesis, effectively removing this region from the list of significant determinants of PD risk.
Results of this study were published in the European Journal of Human Genetics.