Positron emission tomography reveals strong genetic influence in Parkinson's disease

Parkinson's disease: current and future challenges

In 15 years, we will mark the 200th anniversary of the James Parkinson's original description of the disease that now bears his name (An Essay on the Shaking Palsy, Sherwood, Neely and Jones London, 1817). Perhaps, one of the most exciting but daunting questions we face at this moment is whether or not we can unravel the etiology of the disease by that time. If we are to accomplish such an ambitious goal, we must determine the resources that will be required to make it happen, and identify the areas of scientific focus that should receive the greatest attention. One issue that will have great bearing on the allocation of research resources relates to the relative roles of genes versus environment in disease causation. For reasons that will become clear in this article, this has a remained surprisingly controversial area. Ironically, this controversy has even spilled over to the very definition of Parkinson's disease, and even whether or not it should be considered a disease entity. In this article, the enduring "genes versus environment" debate is reviewed, with a goal of putting it into a broader perspective. Issues surrounding disease definition and terminology are also addressed in detail, because of the need to have clarity of thought and vision if research on the cause is to proceed in an orderly (and hopefully expeditious) manner. Finally, issues relating future research directions are summarized, with the goal of identifying the pieces of the Parkinson's puzzle that are going to have to be put together if we are to solve this mysterious disease.

Polymorphisms of the parkin gene in sporadic Parkinson's disease among Chinese in Taiwan

The role of genetics in Parkinson's disease (PD), previously controversial, is now documented by several studies. A major breakthrough has been the discovery of two single-gene defects in familial PD. A single base pair change at position 209 from G to A (G209A) in the fourth exon of the alpha-synuclein gene has been identified in cases of autosomal dominant familial PD. Mutations in the Parkin gene can induce autosomal recessive juvenile parkinsonism. A polymorphism of R/W366 in the Parkin gene was found to be associated with a protective factor for sporadic PD. We surveyed the polymorphisms of the Parkin gene, including S/N167, R/W366 and V/L380, in 92 cases of sporadic PD and 98 nonaffected individuals in Taiwanese Chinese. The allele frequencies of these polymorphisms are not significantly different between PD and nonaffected controls. We conclude that polymorphisms of the Parkin gene, S/N167, R/W366, V/L380, are not genetic factors for sporadic PD among Chinese in Taiwan.

Epidemiology of Parkinson's disease and akinetic syndromes

New reports of the incidence, prevalence and mortality of Parkinson's disease and parkinsonism are reviewed. Evidence for occupational and lifestyle risk factors and protective factors is updated. Recent genetic epidemiology studies of parkinsonism in twins and families, and studies that investigated imaging and physiologic markers of dopaminergic function in members without parkinsonism are presented.