Scientists at the Icelandic genomics company DeCode Genetics, working with colleagues at the National University Hospital in Reykjavik, have presented at last week's meeting of the American Society for Human Genetics in San Diego a poster suggesting they may have mapped a gene for sporadic, late-onset Parkinson's disease to chromosome 1. The scientists have not yet identified the gene, says DeCode spokesman Edward Farmer.
If this preliminary evidence holds up, it could become important because all currently known Parkinson's mutations cause early-onset forms of the disease and account for only a small fraction of overall cases. Late-onset Parkinson's is the most common form.
The work advances a recent study suggesting a familial component to late-onset Parkinson's (Sveinbjornsdottir, S. et al.). It tracked the genealogical roots of 772 people with PD in a database containing genealogic information on more than 600,000 people in Iceland during the past 11 centuries, and it found that the cases were more related to each other than to random members of the population.
In the current work, A. Hicks, Kari Stefansson, and others cross-matched a nationwide genealogy database with a population-based list of Icelandic Parkinson's disease patients to search for families with more than one patient. Using 781 microsatellite markers, they scanned the genomes of 117 patients and 168 unaffected relatives within 51 families, they write in the conference abstract. They found significant linkage (lod score 4.9) to a new gene region not previously implicated in PD, and they designate this region PARK7.—Gabrielle Strobel
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- Sveinbjörnsdottir S, Hicks AA, Jonsson T, Pétursson H, Guğmundsson G, Frigge ML, Kong A, Gulcher JR, Stefansson K. Familial aggregation of Parkinson's disease in Iceland. N Engl J Med. 2000 Dec 14;343(24):1765-70. PubMed.
- Hicks AA, Pétursson H, Jónsson T, Stefánsson H, Jóhannsdóttir HS, Sainz J, Frigge ML, Kong A, Gulcher JR, Stefánsson K, Sveinbjörnsdóttir S. A susceptibility gene for late-onset idiopathic Parkinson's disease. Ann Neurol. 2002 Nov;52(5):549-55. PubMed.