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Local=A0=20 Yahoo! News Health Headlines=20 ------------------------------------------------------------------------ Monday March 2 1:06 PM EST=20 Suspected Parkinson's Gene Located NEW YORK (Reuters) -- Scientists have located a gene shared by a group = of families with a predisposition to Parkinson's disease, according to a = report in Nature Genetics.=20 The genetic mutation, located on chromosome 2, "appears to be involved = in the development of parkinsonism closely resembling sporadic (typical) = Parkinson's disease," according to researchers led by Dr. Thomas Gasser = of Ludwig-Maximilians-Universitat in Munchen, Germany.=20 Parkinson's disease is a chronic neurological illness which causes = tremors, loss of facial expression, and a gradual deterioration in = muscle control.=20 The German discovery follows a recent announcement that a = Parkinsons-linked gene discovered earlier this year among the members of = one Italian family might not, after all, be linked to the most typical = and widespread form of the disease. As reported by Reuters on February = 25th, a study led by Dr. J. William Langston of the Parkinson's = Institute in Sunnyvale, California, failed to find the gene in the DNA = of 100 Parkinson's patients. Langston believes the gene carried by the = Italian family is "not common in the general population."=20 However, the German researchers believe the mutation they have located = may be more likely to play a role in the development of Parkinson's. = They note that the gene is shared by seven different north-European = families, and produces at least "four cardinal signs of (typical) = Parkinson's disease," including disease onset at a typically late age = (around 60 years). Affected family members also respond well to = treatment with the neurotransmitter L-dopa; a response similar to that = of patients suffering from the most common form of Parkinsons.=20 The investigators describe the gene as "autosomal dominant," meaning = that a child need only receive the gene from one parent to run the risk = of developing Parkinson's in later life. Still, the researchers note = that only 40% of family members who carry the gene go on to develop the = disease. They believe that "other genetic or non-genetic factors = (besides the presence of the 2p13 gene) may determine severity of (gene) = expression."=20 The researchers believe a common mutation, occurring in the distant = past, may link at least two of the affected families. "The ancestors of = both families... originate from neighbouring regions of southern Denmark = and northern Germany," explain the study authors. "In view of the close = historical ties between these regions, a common ancestry seems possible. = This finding may thus point to the presence of a founder mutation which = might also be present in additional Parkinson's disease cases from this = area." SOURCE: Nature Genetics (1998;18:262-265)