Wikipedia has
general information about Parkinson's
disease (PD), including
a genetics section.
Many SNPs have been reported to be associated with risk, but few
have shown significant odds or have been robustly replicated. The
following genes are reported to affect risk of Parkinson's:
rs112176450, also known as Arg1205His, is one of several rare mutations in this gene which are associated with autosomally dominant forms of familial Parkinson's disease
rs35095275, also known as L444P, appears to increase the odds of developing Parkinson's disease by at least 5 fold, lowering the age of onset by about 4 years, across all ethnicities studied. [PMID 19846850]
GRIN2A, a glutamate receptor gene
GSTP1, a detoxification enzyme
Variations have been linked to earlier onset of Parkinson's disease, especially in patients exposed to herbicides. [PMID 17190945]
TNF-alpha promoter [PMID 17192953]
rs34637584, also known as G2019S
Two studies have concluded that the risk of developing Parkinson's disease upon exposure to pesticides is increased from 3 to 8 fold among carriers of CYP2D6*4 (rs3892097(A)) alleles. The risk appears proportional to the degree of pesticide exposure, with no additional risk for CYP2D6*4 carriers with no pesticide exposure, and the highest increased risk of developing Parkinson's seen for CYP2D6*4 carriers with frequent exposure to pesticides. [PMID 14991823, PMID 15174030]
SLC6A3, encoding a dopanine transporter
With pesticide exposure, the risk associated with these alleles is 6X higher. [PMID 16963468]
rs287235 and rs838552 have been linked to Parkinson's disease [PMID 16917932] Having two copies of the risk variant does not lead to a more severe form [3]
rs356219 a tagging SNP for a Parkinson's disease haplotype the "protective" genotype 259/259 of the repeat NACP-Rep1 is associated with lower protein levels in blood than genotypes 261/261, 259/261, and 259/263 [PMID 18162487]
Various SNPs in the NOS1 and NOS2A genes were somewhat associated with sporadic Parkinson's disease and/or age of onset, with a subset also interacting with either smoking or pesticides. [PMID 18663495]
The SREBF1 and SREBF2 genes, which are involved in lipid metabolism, have been implicated in type-2 diabetes [PMID 18192539], Parkinson's disease [PMID 21738487]], and schizophrenia [PMID 18936756].
SNPs in this gene may influence levodopa dosage used to treat Parkinson's disease patients. [PMID 18698234]
A significant association was seen between caffeine intake and the onset of PD (P=2.01×10(-5)), with the odds ratio for moderate and high drinkers at 0.71 [95% confidence interval (CI): 0.50-1.00] and 0.47 (95% CI: 0.34-0.65), respectively against the low drinkers. [PMID 18075470] (P=0.08).
rs1559085 and other SNPs [PMID 20127884]
In
2011 23andMe published
a paper
in plos on Parkinson's
disease which
implicated rs6812193 and rs11868035 while
confirming many old associations.
Note
that a 2006 survey of many common genetic variations that may be
related to PD [4] has
been publicly released; the conclusion at that time was that no
single SNP (from 400,00 on Illumina microarrays) was statistically
significant enough to indicate (by itself) increased risk of
Parkinson's. [PMID
17052657]
A 2007 report indicates that models built up from combinations of variations (i.e., SNPs) in "axon guidance pathway" genes can robustly score Parkinson's susceptibility (including age of onset). [PMID 17571925] A follow-up study published in January 2008 presents a model combining ~50 SNPs from genes in axon guidance pathways said to predict susceptibility to Parkinson's disease, survival free of Parkinson's, and age of onset. 10.1371/journal.pone.0001449; Medpage news article However, an independent 2008 study to replicate this not only did not, but reported that SNPs from randomly chosen genes fit to a model using similar methods seemed to give just as significant results as SNPs from axon guidance genes. In other words, the model was deemed highly "overfitted," calling all the results into question. [PMID 18628988]
The following list of additional genes that may affect risk of Parkinson's appeared in an article in The Lancet in February 2011. doi:10.1016/S0140-6736(10)62345-8
rs10513789 Each G allele is associated with 0.8 times lower odds of Parkinson's disease, according to research published by 23andMe [PMID 21738487]