A team of American and French researchers has discovered duplication of the alpha-synuclein gene causes Parkinson's disease in a French family.
In affected individuals, age of onset, symptoms and symptom progression are similar to that observed in people with sporadic or unexplained cases of Parkinson's disease.
The findings, reported in the Sept. 25 issue of Lancet, suggest a direct relationship between the amount of alpha-synuclein produced, the onset of Parkinson's disease, its severity and progression.
The research was led by Matthew Farrer, Ph.D. (Morris K. Udall Parkinson's Disease Research Center of Excellence at Mayo Clinic, Jacksonville, Fla.), Marie-Christine Chartier-Harlin, Ph.D., and Alain Destee, M.D. (Department of Neurology and INSERM, Lille, France).
Point mutations in the alpha-synuclein gene have previously been linked to the development of familial forms of Parkinson's disease. This led to the discovery that the encoded protein is a major component of Lewy bodies, the cellular inclusions in surviving brain cells. Lewy bodies are the key pathologic hallmark of sporadic Parkinson's disease and related disorders, including dementia with Lewy bodies, multiple system atrophy and neurodegeneration with brain iron accumulation.