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- Berge-Seidl, Victoria, et al.
(författare)
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The GBA variant E326K is associated with Parkinson's disease and explains a genome-wide association signal
- 2017
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Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 658, s. 48-52
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Coding variants in the GBA gene have been identified as the numerically most important genetic risk factors for Parkinson's disease (PD). In addition, genome-wide association studies (GWAS) have identified associations with PD in the SYT11-GBA region on chromosome 1q22, but the relationship to GBA coding variants have remained unclear. The aim of this study was to sequence the complete GBA gene in a clinical cohort and to investigate whether coding variants within the GBA gene may be driving reported association signals. Methods: We analyzed high-throughput sequencing data of all coding exons of GBA in 366 patients with PD. The identified low-frequency coding variants were genotyped in three Scandinavian case-controls series (786 patients and 713 controls). Previously reported risk variants from two independent association signals within the SYT11-GBA locus on chromosome 1 were also genotyped in the same samples. We performed association analyses and evaluated linkage disequilibrium (LD) between the variants. Results: We identified six rare mutations (1.6%) and two low-frequency coding variants in GBA. E326K (rs2230288) was significantly more frequent in PD patients compared to controls (OR 1.65, p = 0.03). There was no clear association of T369M (rs75548401) with disease (OR 1.43, p = 0.24). Genotyping the two GWAS hits rs35749011 and rs114138760 in the same sample set, we replicated the association between rs35749011 and disease status (OR 1.67, p = 0.03), while rs114138760 was found to have similar allele frequencies in patients and controls. Analyses revealed that E326K and rs35749011 are in very high LD (r(2) 0.95). Conclusions: Our results confirm that the GBA variant E326K is a susceptibility allele for PD. The results suggest that E326K may fully account for the primary association signal observed at chromosome 1q22 in previous GWAS of PD.
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| 3. |
- Lill, Christina M., et al.
(författare)
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The role of TREM2 R47H as a risk factor for Alzheimer's disease, frontotemporal lobar degeneration, amyotrophic lateral sclerosis, and Parkinson's disease
- 2015
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 11:12, s. 1407-1416
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Tidskriftsartikel (refereegranskat)abstract
- A rare variant in TREM2 (p.R47H, rs75932628) was recently reported to increase the risk of Alzheimer's disease (AD) and, subsequently, other neurodegenerative diseases, i.e. frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Here we comprehensively assessed TREM2 rs75932628 for association with these diseases in a total of 19,940 previously untyped subjects of European descent. These data were combined with those from 28 published data sets by meta-analysis. Furthermore, we tested whether rs75932628 shows association with amyloid beta (Ab42) and total-tau protein levels in the cerebrospinal fluid (CSF) of 828 individuals with AD or mild cognitive impairment. Our data show that rs75932628 is highly significantly associated with the risk of AD across 24,086 AD cases and 148,993 controls of European descent (odds ratio or OR = 2.71, P = 4.67 x 10(-25)). No consistent evidence for association was found between this marker and the risk of FTLD (OR = 2.24, P = .0113 across 2673 cases/9283 controls), PD (OR 5 1.36, P = .0767 across 8311 cases/79,938 controls) and ALS (OR 5 1.41, P = .198 across 5544 cases/7072 controls). Furthermore, carriers of the rs75932628 risk allele showed significantly increased levels of CSF-total-tau (P = .0110) but not Ab42 suggesting that TREM2's role in AD may involve tau dysfunction. (C) 2015 The Alzheimer's Association.
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| 4. |
- Rengmark, Aina, et al.
(författare)
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Low frequency of GCH1 and TH mutations in Parkinson's disease
- 2016
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1353-8020 .- 1873-5126. ; 29, s. 109-111
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Tidskriftsartikel (refereegranskat)abstract
- Background: The causes of Parkinson's disease (PD) are unknown in the majority of patients. TheGCH1 gene encodes GTP-cyclohydrolase I, an important enzyme in dopaminesynthesis. Co-occurrence of dopa-responsive dystonia (DRD) and a PD phenotype has been reported in families with GCH1 mutations. Recently, rare coding variants in GCH1were found to be enriched in PD patients, indicating a role for the enzyme in theneurodegenerative process.Methods: To further elucidate the contribution of GCH1 mutations to sporadic PD, we examined its coding exons in a targeted deep sequencing study of 509 PD patients (mean age at onset 56.7 ± 12.0 years) and 230 controls. We further included the tyrosine hydroxylasegene TH, also known to cause DRD. Gene dose assessments were performed to screen for large copy number variants in a subset of 48 patients with early-onset PD.Results: No putatively pathogenic GCH1 mutations were found. The frequency of rare heterozygous variants in the TH gene was 0.69% (7/1018) in the patient group and 0.22% (1/460) in the control group (p = 0.45).Conclusions: Previous studies have found that coding variants in the GCH1 gene may be considered a risk factor for PD. Our study indicates that mutations in GCH1 are rare in late-onset PD. Several patients carried heterozygous variants in the TH gene that may affect protein function. Our study was not designed to determine with certainty if any of these variants play a role as risk factors for late-onset PD.
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