Project description:BackgroundFibroblast growth factor 20 (FGF20) is a neurotrophic factor preferentially expressed in the substantia nigra of rat brain and could be involved in dopaminergic neurons survival. Recently, a strong genetic association has been found between FGF20 gene and the risk of suffering from Parkinson's disease (PD). Our aim was to replicate this association in two independent populations.MethodsAllelic, genotypic, and haplotype frequencies of four biallelic polymorphisms were assessed in 151 sporadic PD cases and 186 controls from Greece, and 144 sporadic PD patients and 135 controls from Finland.ResultsNo association was found in any of the populations studied.ConclusionTaken together, these findings suggest that common genetic variants in FGF20 are not a risk factor for PD in, at least, some European populations.
Project description:Activation of the NLRP3 inflammasome has been implicated in Parkinson's disease (PD) based on in vitro and in vivo studies. Clinical trials targeting the NLRP3 inflammasome in PD are ongoing. However, the evidence supporting NLRP3's involvement in PD from human genetics data is limited. We analyzed common and rare variants in NLRP3 inflammasome-related genes in PD cohorts, performed pathway-specific polygenic risk score (PRS) analyses, and studied causal associations using Mendelian randomization (MR) with the NLRP3 components and the cytokines IL-1β and IL-18. Our findings showed no associations of common or rare variants, nor of the pathway PRS with PD. MR suggests that altering the expression of the NLRP3 inflammasome, IL-1β, or IL-18, does not affect PD risk or progression. Therefore, our results do not support a role for the NLRP3 inflammasome in PD pathogenesis or as a target for drug development.
Project description:UCHL1 has been proposed as a candidate gene for Parkinson's disease (PD). A meta-analysis of white and Asian subjects reported an inverse association between the non-synonymous UCHL1 S18Y polymorphism and PD risk. However, this finding was not replicated in a large case-control study and updated meta-analysis restricted to white subjects. We performed a case-control study of 1757 PD patients recruited from movement disorder clinics and 2016 unrelated controls from four regions of the United States. All subjects self-reported as white. We did not observe evidence for an association between S18Y genotypes and PD (overall P-value for association: P = 0.42). After adjustment for age, sex, and recruitment region, the odds ratio for Y/S versus S/S was 0.91 (95% CI: 0.78-1.06) and for Y/Y versus S/S was 0.87 (95% CI: 0.58-1.29). We also did not observe a significant association for recessive or dominant models of inheritance, or after stratification by age at onset, age at blood draw, sex, family history of PD, or recruitment region. Our results suggest that UCHL1 S18Y is not a major susceptibility factor for PD in white populations although we cannot exclude the possibility that the S18Y variant exerts weak effects on risk, particularly in early-onset disease.
Project description:Recently, a novel variant p.Y314S in UQCRC1 has been implicated as pathogenic in Parkinson's disease (PD). In the present study, we aimed to examine the association of UQCRC1 with PD in large cohorts of European origin. We examined common and rare genetic variation in UQCRC1 using genome-wide association study data from the International Parkinson Disease Genomics Consortium, including 14,671 cases and 17,667 controls, and whole-genome sequencing data from the Accelerating Medicines Partnership-Parkinson's disease initiative, including 1647 patients with PD and 1050 controls. No common variants were consistently associated with PD, and a variety of burden analyses did not reveal an association between rare variants in UQCRC1 and PD. Therefore, our results do not support a major role for UQCRC1 in PD in the European population, and additional studies in other populations are warranted.
Project description:Background:The phospholipase A2 Group 6 (PLA2G6, also known as PLA2, PARK14, and iPLA2) gene encodes a group VIA calcium-independent phospholipase A2. Genetic polymorphism of PLA2G6 has been indicated to be involved in conferring susceptibility for Parkinson's disease (PD), whereas conclusive results have not been obtained. Thus, we intended to conduct a systematic review to determine if PLA2G6 genetic variation confers a greater susceptibility to PD. Methods:All case-control studies that investigated the association of the PLA2G6 polymorphisms with the risk of PD published before 15 July 2018 were included. The literature was comprehensively searched and identified in five English databases (EBSCO, Pubmed, OVID, EMBASE and ISI Web of Knowledge) and four Chinese databases (Wanfang database, Chinese Biomedical Literature Database, China Academic Journals Database and VIP database). We performed analyses of study characteristics, heterogeneity, and forest plot in analyses analogous to dominant, codominant and additive models with the pooled odds ratio (OR) in fixed- or random-effects models as the measure of association. Results:A total of 664 potentially relevant studies were retrieved with the initial search, of which eight studies fulfilled the inclusion criteria, and included 2,779 PD patients and 3,291 control participants,. Among all the reported 27 genetic variants, 15 single nucleotide polymorphisms (SNPs) were present only in patients, and only five available SNPs (rs2267369, rs140758033, c.1959T>A (Gly653Gly), rs76718524, rs199935023) were pooled in the meta-analysis. However, there was no evidence for a significant association between the five SNPs and PD risk in dominant, codominant and allele models, suggesting a lack of association between PLA2G6 genetic variation and PD susceptibility. Conclusion:The present study assessed the association of PLA2G6 genetic polymorphism with the risk PD, and the result strongly demonstrates that PLA2G6 polymorphism is not associated with PD susceptibility.
Project description:Parkin (PRKN) mutations are a common cause of early-onset parkinsonism, however the role of this gene in typical late-onset Parkinson's disease (PD) remains unresolved. A single nucleotide polymorphism in the promoter region (PRKN-258; rs9347683) has been observed to associate with PD, affect age-at-onset (AAO) of symptoms, and to functionally effect differential expression of the PRKN transcript. In the present study, PRKN-258 did not associate with PD, and no evidence for an AAO effect was observed in three age and gender-matched Caucasian patient-control series from Norway, Ireland and the US. These data do not support a role for this common variant in PD etiology.
Project description:Mutations in TMEM230 have recently been associated to Parkinson's disease (PD). To further understand the role of this gene in the Caucasian population, we interrogated our large repository of next generation sequencing data from unrelated PD cases and controls, as well as multiplex families with autosomal dominant PD. We identified 2 heterozygous missense variants in 2 unrelated PD cases and not in our control database (p.Y106H and p.I162V), and a heterozygous missense variant in 2 PD cases from the same family (p.A163T). However, data presented herein is not sufficient to support the role of any of these variants in PD pathology. A series of unified sequence kernel association tests also failed to show a cumulative effect of rare variation in this gene on the risk of PD in the general Caucasian population. Further evaluation of genetic data from different populations is needed to understand the genetic role of TMEM230 in PD etiology.
Project description:BACKGROUND AND AIMS:Similar clinical and pathological features have been observed in Alzheimer's disease (AD) and Parkinson's disease with dementia (PDD). Both the peroxisome proliferator-activated receptor-? (PPAR-?) gene and the peroxisome proliferator-activated receptor-? coactivator-1? (PGC-1?) gene are candidates modifying the risk for both diseases. The aim of this study was to clarify whether common single nucleotide polymorphisms (SNPs) of the PPAR-? gene and the PGC-1? gene affect the onset of AD and PDD genetically. METHODS:Four exonic SNPs of both genes (rs1801282 and rs3856806 of the PPAR-? gene, rs3736265 and rs8192678 of the PGC-1? gene) were genotyped in 171 AD patients, 136 age-matched controls and 53 PDD patients. Haplotype analysis and logistic regression analysis with apolipoprotein E (APO E) status were performed for AD. RESULTS:There was no statistical difference between AD cases and controls for the 4 SNPs, nor was there any statistical difference between PDD cases and controls for the 4 SNPs. We could not find any synergetic associations between these SNPs, APO E4 and AD. CONCLUSIONS:The 4 SNPs studied here did not influence the risk for AD in a Japanese population. As the number of PDD cases was small, comprehensive genetic studies considering diabetes would be needed.
Project description:Low DJ-1 protein level caused by DJ-1 gene mutation leads to autosomal recessive Parkinson's disease (PD) due to impaired antioxidative activity. In sporadic PD patients, although mutations were rarely found, lower DJ-1 protein level was also reported. Dysregulation of DJ-1 gene expression might contribute to low DJ-1 protein level. Since the promoter is the most important element to initiate gene expression, whether polymorphisms in the DJ-1 promoter result in the dysregulation of gene expression, thus leading to low protein level and causing PD, is worth exploring. The DJ-1 promoter region was sequenced in a Chinese cohort to evaluate possible links between DJ-1 promoter polymorphisms, PD risk and clinical phenotypes. Dual-luciferase reporter assay was conducted to evaluate the influence of promoter polymorphisms on DJ-1 transcriptional activity. Related information in an existing genome-wide association studies (GWAS) database were looked up, meta-analysis of the present study and other previous reports was conducted, and expression quantitative trait loci (eQTL) analysis was performed to further explore the association. Three single nucleotide polymorphisms (SNPs) (rs17523802, rs226249, and rs35675666) and one 18 bp deletion (rs200968609) were observed in our cohort. However, there was no significant association between the four detected genetic variations and the risk of PD either in allelic or genotype model, in single-point analysis or haplotype analysis. This was supported by the meta-analysis of this study and previous reports as well as that of GWAS database PDGene. Dual luciferase reporter assay suggested these promoter polymorphisms had no influence on DJ-1 transcriptive activity, which is consistent with the eQTL analysis results using the data from GTEx database. Thus, DJ-1 promoter polymorphisms may play little role in the dysregulation of DJ-1 expression and PD susceptibility in sporadic PD.