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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.=20 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.=20 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.=20 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."=20 "This gene is obviously not common in the general population," Langston = said.=20 The study was initiated after widespread confusion among patients and = physicians as to the necessity for genetic testing in families affected = by Parkinson's.=20 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."=20 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.=20 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) =