Parkinson's disease (PD) is a complex neurodegenerative condition in which genetic and environmental factors interact to contribute to its etiology. Remarkable progress has been made in deciphering ...disease etiology through genetic approaches, but there is limited data about how environmental and genetic factors interact to modify penetrance, risk, and disease severity. Here, we provide insights into environmental modifiers of PD, discussing precedents from other neurological and non‐neurological conditions. Based on these examples, we outline genetic and environmental factors contributing to PD and review potential environmental modifiers of penetrance and clinical variability in monogenic and idiopathic PD. We also highlight the potential challenges and propose how future studies might tackle these important questions. ANN NEUROL 2022;92:715–724
Genetic variation within the mitochondrial pathway contributes to the risk of Parkinson’s disease (PD). Recent genetic analyses have investigated the association between the RHOT1 and RHOT2 genes and ...PD etiology. Furthermore, 4 mutations in the RHOT1 gene (p.R272Q, p.R450C, p.T351A, p.T610A) have been reported to be potentially associated with disease risk. As part of the International Parkinson Disease Genomics Consortium efforts to evaluate reported PD risk factors, we assessed the role of common and low frequency variants in both RHOT1 and also RHOT2 according to the high degree of homology in their amino acid sequences. Utilizing large-scale genotyping and whole-genome sequencing data from the International Parkinson Disease Genomics Consortium and the Accelerating Medicines Partnership – Parkinson Disease initiative, our analyses did not identify evidence to support the hypothesis that RHOT1 and RHOT2 are disease causing or modifying genes for PD risk or age at onset.
Background
Hyperhomocysteinemia is considered an independent risk factor for cognitive impairment.
Objective
To study the correlation between homocysteine levels and cognitive impairment in patients ...with PD.
Methods
We conducted a case–control study that included 246 patients with PD, of whom 32 were cognitively impaired. The levels of homocysteine, folate, and vitamin B12 were measured in peripheral blood. Multivariate logistic regression analysis was applied to determine differences in homocysteine levels between PD patients with and without cognitive impairment. A meta-analysis was performed to clarify the role of Hcy levels in PD with cognitive decline. Five polymorphisms in genes involved in Hcy metabolism, including
MTHFR
rs1801133 and rs1801131,
COMT
rs4680,
MTRR
rs1801394, and
TCN2
rs1801198, were genotyped.
Results
Our case–control study showed that homocysteine levels were associated with cognitive impairment in PD after adjusting for possible confounding factors such as levodopa equivalent daily dose. The results of our meta-analysis further supported the positive association between homocysteine levels and cognition in PD. We found that the
MTHFR
rs1801133 TT genotype led to higher homocysteine levels in PD patients, whereas the
MTHFR
rs1801131 CC genotype resulted in higher folate levels. However, the polymorphisms studied were not associated with cognitive impairment in PD.
Conclusions
Increased homocysteine levels were a risk factor for cognitive decline in PD. However, no association was found between polymorphisms in genes involved in homocysteine metabolism and cognitive impairment in PD. Large-scale studies of ethnically diverse populations are required to definitively assess the relationship between
MTHFR
and cognitive impairment in PD.
Multiple system atrophy (MSA) is an adult-onset, sporadic synucleinopathy characterized by parkinsonism, cerebellar ataxia, and dysautonomia. The genetic architecture of MSA is poorly understood, and ...treatments are limited to supportive measures. Here, we performed a comprehensive analysis of whole genome sequence data from 888 European-ancestry MSA cases and 7,128 controls to systematically investigate the genetic underpinnings of this understudied neurodegenerative disease. We identified four significantly associated risk loci using a genome-wide association study approach. Transcriptome-wide association analyses prioritized USP38-DT, KCTD7, and lnc-KCTD7-2 as novel susceptibility genes for MSA within these loci, and single-nucleus RNA sequence analysis found that the associated variants acted as cis-expression quantitative trait loci for multiple genes across neuronal and glial cell types. In conclusion, this study highlights the role of genetic determinants in the pathogenesis of MSA, and the publicly available data from this study represent a valuable resource for investigating synucleinopathies.
Display omitted
•Generation of a foundational genomic resource in multiple system atrophy•GWAS identifies novel risk loci at GAB1, lnc-LRRC49-3, TENM2, and RABGEF1•Functional genomics implicates USP38-DT, KCTD7, and lnc-KCTD7-2 within these loci•Gene-burden analysis identifies nominal enrichment of rare missense mutations in KCTD7
Chia et al. comprehensively analyzed genome sequence data from patients with multiple system atrophy (MSA) and controls. The study identified four novel risk loci associated with MSA and prioritized significantly associated genes (USP38-DT, KCTD7, and lnc-KCTD7-2) within these loci. This initiative's data constitute a valuable resource for the research community.
TMEM230 has been associated with autosomal dominant Parkinson's disease (PD). Subsequent studies have remained negative, and none of previous described mutation has been reported anymore. We ...investigated the implication of this gene in the PD in a population of 703 PD patients and 695 unrelated healthy controls from southern Spain. Thirteen variants were found, twelve of them observed only in controls or in patients and controls, and one (c.190A>G) observed only in one patient. Subsequent analysis of this variant indicates that probably it is not pathogenic. In addition, we found a variation in the 3'-UTR (rs183551373) and related with the miRNA hsa-miR-4299 but it was observed only in healthy controls. Our results suggest that variants in TMEM230 gene are not associated with the development of PD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The ATP10B gene has been proposed to play an important role in the development of early-onset Parkinson's disease (PD). Nevertheless, various studies have presented controversial conclusions ...regarding the involvement of this gene in PD. Here, we screened 1162 patients with PD, employing a targeted resequencing approach to investigate the putative relevance of this gene in a large independent cohort of these patients from southern Spain. Variations were classified according to the American College of Medical Genetics and Genomics criteria. Association studies were performed using data of a representative healthy Spanish population from the Medical Genome Project. Frequent variants were excluded. A total of 68 variants (rare or very rare) were detected in our cohort. Among ATP10B variant carriers, 12.9 % were putative compound heterozygous carriers; of these, 25 % were patients with early-onset PD. No evidence of a relation between any rare variants of ATP10B and PD risk was observed. Therefore, our results do not support a role for ATP10B in the onset of PD, or in the risk of developing it.
•ATP10B gene have been involved in the development of Parkinson's disease (PD).•We mined a targeted sequencing approach to screen a cohort of patients from Spain.•No evidence of a relation between any rare variants of ATP10B and PD was observed.•Variations in ATP10B do not play a major role in PD, at least in our population.
Both recessive and dominant genetic forms of Parkinson's disease have been described. The aim of this study was to assess the contribution of several genes to the pathophysiology of early onset ...Parkinson's disease in a cohort from central Spain.
We analyzed a cohort of 117 unrelated patients with early onset Parkinson's disease using a pipeline, based on a combination of a next-generation sequencing panel of 17 genes previously related with Parkinson's disease and other Parkinsonisms and CNV screening.
Twenty-six patients (22.22%) carried likely pathogenic variants in PARK2, LRRK2, PINK1, or GBA. The gene most frequently mutated was PARK2, and p.Asn52Metfs*29 was the most common variation in this gene. Pathogenic variants were not observed in genes SNCA, FBXO7, PARK7, HTRA2, DNAJC6, PLA2G6, and UCHL1. Co-occurrence of pathogenic variants involving two genes was observed in ATP13A2 and PARK2 genes, as well as LRRK2 and GIGYF2 genes.
Our results contribute to the understanding of the genetic architecture associated with early onset Parkinson's disease, showing both PARK2 and LRRK2 play an important role in Spanish Parkinson's disease patients. Rare variants in ATP13A2 and GIGYF2 may contribute to PD risk. However, a large proportion of genetic components remains unknown. This study might contribute to genetic diagnosis and counseling for families with early onset Parkinson's disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
