Parkinson's disease genetic study progresses with $8 million grant


INDIANAPOLIS Success in the location of genes potentially involved with the onset of Parkinson's disease has been rewarded with $8.26 million grant renewal from the National Institutes of Health.

Indiana University School of Medicine will serve as the coordinating center for this grant as it did for the initial funding.

The original grant for $6 million in 1998 initiated the largest nationwide study ever conducted on the genetics of the neurodegenerative disease. The study, called Parkinson's Research: The Organized Genetic Initiative (PROGENI) enrolled 600 sibling pairs with the disease from 58 Parkinson's Study Group centers in the United States, Canada and Puerto Rico.

During the first five years, PROGENI researchers determined that a gene known as the parkin gene may indicate a risk factor for developing Parkinson's disease in older adults when one of the two gene pairs is abnormal. Previously, it was believed that the parkin gene only was involved in the development of juvenile Parkinson's disease and only when both copies of the parkin genes were abnormal.

Researchers also narrowed the field of potential genes and believe they have found a gene on chromosome two that may be important in the development of the disease in families with multiple affected members.

"We also have tantalizing hints on the X chromosome, which may be of more importance to men with the disease," said Tatiana Foroud, Ph.D., associate professor of medical and molecular genetics at the Indiana University School of Medicine and the principal investigator for the nationwide PROGENI study.

The discovery of multiple genes that may have an impact on the onset of Parkinson's disease on patients who develop the disease at different ages and in families with multiple affected members is a new development.

"That's how far we've come," said Dr. Foroud. "Five years ago, we had to seriously argue that Parkinson's was genetic to obtain the grant funding. Today, we have proof."

The second phase of the study will recruit an additional 300 sibling pairs with Parkinson's disease. Participants in the trial will answer health questions, undergo a clinical examination and donate a blood sample from which DNA is extracted. Siblings do not need to live in the same part of the country since the study is being conducted at multiple sites. (See the Web site listed below for study sites.)

"Our mission in the next five years is to find the gene on chromosome two that affects families with multiple members afflicted with Parkinson's," said Dr. Foroud. "We also intend to nail down what the parkin gene does."

In addition to the nationwide study, the IU School of Medicine is conducting a related study called PROGENI CARES for residents of Indiana. This study allows friends and same-sex in-laws of individuals with Parkinson's disease to help find the affected genes. Dr. Foroud and her fellow researchers are seeking 500 individuals with Parkinson's disease and 500 unrelated individuals without the disease. Each person must be willing to donate a blood sample. Names are kept confidential and the DNA is stored with no personal identification, such as date of birth or Social Security number.

The discoveries may have an enormous impact on early detection, treatment and on the development of new and more effective drugs for treatment of Parkinson's disease, she said.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
    Published on All rights reserved.