The Genetic Epidemiology of Parkinson’s Disease.
The cause of Parkinson’s disease (PD) is unknown. The major risk
factors identified to date are family history, age, and elements of
rural living. Nearly one-third of all PD cases are familial, a small
subset of which appears autosomal dominant; however, the majority
exhibit no clear inheritance pattern. Autosomal dominant PD is
genetically heterogeneous: two PD genes have been mapped to chromosomes 2
and 4 and there may be additional as yet unidentified genes.
The common forms of
The Genetic Epidemiology of Parkinson’s Disease
familial and sporadic cases-appear to involve a complex interplay of
genetic susceptibility and environmental exposure. The observations that
rural residence and pesticide exposure increase the risk of developing
PD, and that a synthetic drug,
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, can cause parkinsonism,
suggest that at least a subset of PD may be caused by a toxin.
Furthermore, modest but significant associations have been reported
between PD susceptibility and genes that regulate metabolism of drugs
and neurotoxins.
There is also evidence for mitochondrial dysfunction in PD, a finding
that was recently traced to anomalies in mitochondrial DNA. At the
present time, the genetics of PD appear to be complex, involving
multiple nuclear genes and possibly mitochondrial genes as well. ( From
ncbi.nlm.nih.gov about The
Genetic Epidemiology of Parkinson’s Disease ).
