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Study Disputes Parkinson's-Gene Link NEW YORK (Reuters) -- Researchers say the recent announcement of the discovery of a gene suspected of triggering Parkinson's disease may have been premature. A report in the current issue of the journal Neurology concludes that the gene has been found in only one family -- and the neurological disorder that runs in that family is not typical Parkinson's disease. It appears that the gene in question has no link to the vast majority of Parkinson's cases. As reported by Reuters on June 26, 1997, researchers at the National Human Genome Research Institute, part of the National Institute of Health (NIH) in Bethesda, Maryland, announced the discovery of a genetic mutation in the members of a specific Italian family, called the Contursi kindred. Family members seem especially prone to a form of early-onset Parkinson's disease; a chronic neurological illness that causes tremors and a gradual deterioration in muscle control. However, researchers led by neurologist Dr. J. William Langston of The Parkinson's Institute in Sunnyvale, California, now say the gene plays no role in the vast majority of cases. They closely examined the DNA structure of a group of American Parkinson's patients and found the mutation "was not present in any of the 100 patients studied." "This gene is obviously not common in the general population," Langston said. The study was initiated after widespread confusion among patients and physicians as to the necessity for genetic testing in families affected by Parkinson's. But Langston is now of the opinion that the Contursi clan "is probably the only family on earth with this mutation. He believes "the news about (the gene's) discovery was overgeneralized, causing pain and concern in families." In fact, the California team are not even sure if affected members of the Contursi clan are suffering from Parkinson's at all. "The Contursi kindred frequently have atypical clinical features, including a more rapid progression of disease," than is usual among Parkinson's patients. In addition, the researchers note that the Contursi illness does not seem to respond to treatment with L-dopa, the neurological drug which has proven successful in slowing down the ravages of Parkinson's disease. But Langston believes the discovery of the gene is "tremendously important." He points out that the Contursi gene triggers the production of a protein able to kill brain cells. "This discovery may allow us to learn a huge amount about how an abnormal gene can cause a disease similar to Parkinson's disease, which may help us learn more about what causes Parkinson's itself," he said. SOURCE: Neurology (1998;50:513-514) Copyright © 1998 Reuters Ltd. All rights reserved. Republication or redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.