Table 1.

Genes investigated for Parkinson’s disease and pesticides related GxE interactions

Gene	Gene function	Relevant variant/s	Variant/s function
DAT/SLC6A3	Encodes a dopamine transporter, responsible for the reuptake of dopamine into presynaptic neurons	5′ clade & 3′ VNTR 9-repeat	Clade: conflicting evidence, but likely increased function/levels with clade A; VNTR: 9-repeat associated with higher striatal DAT
ABCB1	Encodes P-glycoprotein 1, responsible for transporting many substances in- and out of cells and across the BBB	rs1045642 & rs2032582	rs1045642 been shown to alter substrate specificity and rs2032582 alters P-gp expression
PON1	Encodes the paraoxonase enzyme, which detoxifies organophophates	L55M & Q192R	L55M & Q192R influences enzyme activity, M or Q allele carriers are considered “slower” metabolizers
NOS1	Encodes neuronal nitric oxide synthase, which synthesizes nitric oxide	rs2682826	Unknown function; tag SNP
ALDH2	Encodes ALDH, which metabolizes biogenic amine-related aldehydes, including the highly toxic dopamine metabolite DOPAL	rs737280	Unknown function; tag SNP
SKP1	Encodes S-phase kinase-associated protein 1, a key component of E3 ubiquitin ligases	rs2284312	Unknown function; tag SNP
HLA-DR	Encodes HLA-DR, an MCH class II cell surface receptor responsible for presenting peptide antigens to immune cells to a elicit T-cell response	rs3129882	Unknown function; GWAS discovered tag SNP

Abbreviations: VNTR=variable number tandem repeat; P-gp=P-glycoprotein 1; ALDH=aldehyde dehydrogenase; SNP=single nucleotide polymorphism; MCH=major histocompatibility complex; GWAS-genome wide association study; DOPAL=3,4-dihydroxyphenylacetaldehyde; BBB=blood brain barrier