UCHL-1 is not a Parkinson's disease susceptibility gene

European Journal of Neurology, 2007

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.

Parkinsonism & Related Disorders, 2011

UCHL1 plays an important role in the ubiquitin-proteasome system and is a biologically plausible candidate gene for Parkinson's disease (PD). However, results from genetic association studies of the UCHL1 S18Y polymorphism have been equivocal. Meta-analyses indicate that the polymorphism's risk effect might be restricted to Asian populations and early-onset disease. To further explore the role of UCHL1 in PD, we genotyped S18Y in 605 PD patients and 1620 controls of Japanese ancestry. We did not find evidence of an association in the overall sample (SY vs. SS: adjusted OR = 1.11, P = 0.37; YY vs. SS: adjusted OR = 1.01, P = 0.94). In the earlyonset stratum, however, we observed a trend toward a reduction in risk for those with the Y allele (SY vs. SS, adjusted OR, 0.75; 95% CI, YY vs. SS, OR, 0.64; 95% CI,14; trend test, P = 0.12). These results indicate that, if involved in PD, the S18Y variant is not a major determinant of risk and its effect might be restricted to early-onset disease.

Neurobiology of Aging, 2010

The inverse association of the functional ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y variant with Parkinson's disease (PD) among Caucasian populations has been debated. We conducted a large-scale analysis to investigate the age-of-onset effect of the UCHL1 variant in PD among ethnic Chinese. Individual data sets from 5 centers comprising a total of 4088 study subjects were analyzed. In the univariate analysis, only data from 1 center showed a trend towards a protective effect among young subjects. However, in the combined analysis, no significant association between the UCHL1 variant and PD was detected (A allele frequency 0.531 vs. 0.528, p = 0.87, OR 1.01, 95% CI 0.92-1.1). Among subjects less than 60 years old, the OR is 0.99 (95% CI 0.84-1.16, p = 0.88). A multivariate logistic regression analysis showed that family history, UCHL1 variant and the interaction of UCHL1 variant and age at onset (p = 0.816) were not significantly associated with PD.

Annals of Neurology, 2004

The reported inverse association between the S18Y variant of the ubiquitin carboxy-terminal hydrolase L1 (UCHL1) gene and Parkinson's disease (PD) has strong biological plausibility. If confirmed, genetic association of this variant with PD may support molecular targeting of the UCHL1 gene and its product as a therapeutic strategy for PD. In this light, we performed a collaborative pooled analysis of individual-level data from all 11 published studies of the UCHL1 S18Y gene variant and PD. There were 1,970 cases and 2,224 unrelated controls. We found a statistically significant inverse association of S18Y with PD.

BMC Neurology, 2012

Background: A recent meta-analysis on the UCHL1 S18Y variant and Parkinson's disease (PD) showed a significant inverse association between the Y allele and PD; the individual studies included in that meta-analysis, however, have produced conflicting results. We examined the relationship between UCHL1 S18Y single nucleotide polymorphism (SNP) and sporadic PD in Japan. Methods: Included were 229 cases within 6 years of onset of PD, defined according to the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 357 inpatients and outpatients without neurodegenerative disease. Adjustment was made for sex, age, region of residence, smoking, and caffeine intake. Results: Compared with subjects with the CC or CA genotype of UCHL1 S18Y SNP, those with the AA genotype had a significantly increased risk of sporadic PD: the adjusted OR was 1.57 (95 % CI: 1.06 -2.31). Compared with subjects with the CC or CA genotype of UCHL1 S18Y and the CC or CT genotype of SNCA SNP rs356220, those with the AA genotype of UCHL1 S18Y and the TT genotype of SNP rs356220 had a significantly increased risk of sporadic PD; the interaction, however, was not significant. Our previous investigation found significant inverse relationships between smoking and caffeine intake and PD in this population. There were no significant interactions between UCHL1 S18Y and smoking or caffeine intake affecting sporadic PD. Conclusions: This study reveals that the UCHL1 S18Y variant is a risk factor for sporadic PD. We could not find evidence for interactions affecting sporadic PD between UCHL1 S18Y and SNCA SNP rs356220, smoking, or caffeine intake.

Neuroscience Letters, 2005

To avoid the possible confounding effect of population stratification, we employed a discordant sibling study design and a liberalization of the sibling transmission disequilibrium test to confirm the association of the S18Y variant of the ubiquitin carboxi-terminal hydrolase L1 (UCHL1) gene with Parkinson's disease (PD). The study included 497 case-control pairs (427 case-unaffected sibling pairs and 70 caseunrelated control pairs). Analyses confirmed a significant inverse association of the UCHL1 S18Y polymorphism with PD overall (OR = 0.18, 95% CI = 0.05-0.64, p = 0.002, recessive model) and in several strata.

Neuroscience Letters, 2008

Mutation in UCH-L1 has been reported as a rare cause of autosomal dominant Parkinson's disease (PD). A S18Y polymorphism in the same gene has been associated with sporadic PD. We investigated the frequency of this polymorphism among the Han-Chinese ethnic population in a case-control study. A total of 600 patients with PD and 334 unrelated healthy controls were genotyped using PCR-restriction fragment length polymorphism analysis. We did not observe any difference in allele or genotype frequencies between the cases and the controls (P > 0.05). Our results do not support a role for this variant in sporadic PD.

NeuroReport, 2000

Recently, an Ile93Met substitution has been identi®ed in the ubiquitin carboxy-terminal hydrolase L1 (UCHL1) gene in a single German PD family with autosomal dominant inheritance. To determine whether mutations in the UCHL1 gene are causative for Parkinson's disease (PD) a detailed mutation analysis was performed in a large sample of German sporadic and familial PD patients. We found no disease-causing mutation in the coding region of the UCHL1 gene. Direct sequencing revealed six intronic polymorphisms in the UCHL1 gene. Analysis of an S18Y polymorphism in exon 3 of the UCHL1 gene in sporadic PD patients and controls showed carriers of allele 2 (tyrosine) signi®cantly less frequent in patients with a reduced risk of 0.57 (CI 0.36±0.88; p 0.012, p c 0.047, ÷ 2 6.31). Our study shows that sequence variations in the coding region of UCHL1 are a rare event. A protective effect of a certain UCHL1 variant in the pathogenesis of sporadic PD is suggested, underlining the relevance of UCHL1 in neuro

The Lancet Neurology, 2006

Background-A genome-wide association study identified 13 single-nucleotide polymorphisms (SNPs) significantly associated with Parkinson's disease. Small-scale replication studies were largely non-confirmatory, but a meta-analysis that included data from the original study could not exclude all SNP associations, leaving relevance of several markers uncertain.

2021

Human genetics research lacks diversity; over 80% of genome-wide association studies (GWAS) have been conducted on individuals of European ancestry. In addition to limiting insights regarding disease mechanisms, disproportionate representation can create disparities preventing equitable implementation of personalized medicine. This systematic review provides an overview of research involving Parkinson's disease (PD) genetics in under-represented populations (URP), and sets a baseline to measure the future impact of current efforts in those populations. We searched PubMed and EMBASE until October 2021 using search strings for "PD", "genetics", the main "URP", and "lower-to-upper-middle-income countries". Inclusion criteria were original studies, written in English, reporting genetic results on PD patients from non-European populations. Two levels of independent reviewers identified and extracted relevant information. We observed considerabl...