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- Bäckström, David, et al.
(författare)
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PITX3 genotype and risk of dementia in Parkinson's disease : A population-based study
- 2017
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Ingår i: Journal of the Neurological Sciences. - : ELSEVIER SCIENCE BV. - 0022-510X .- 1878-5883. ; 381, s. 278-284
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Tidskriftsartikel (refereegranskat)abstract
- Dementia is a devastating manifestation of Parkinson's disease (PD). This study investigates whether a common polymorphism in the PITX3 gene (rs2281983), which is of importance for the function of dopaminergic neurons, affects the risk of developing dementia in PD and whether it affects dopamine transporter (DAT) uptake. We PITX3 genotyped 133 patients with new-onset, idiopathic PD, participating in a population-based study in Sweden. Patients were followed prospectively during 6-11 years with extensive investigations, including neuropsychology and DAT-imaging with I-123 FP-CIT. The primary outcome was the incidence of PD dementia (PDD), diagnosed according to published criteria, studied by the Kaplan-Meier method and Cox proportional hazards. Performance in individual cognitive domains, the incidence of visual hallucinations, disease progression and striatal DAT uptake on imaging was also investigated. PD patients carrying the PITX3 C allele had an increased risk of developing PDD (hazard ratio: 2.87, 95% CI: 1.42-5.81, p = 0.003), compared to the PD patients homozygous for the T-allele. Furthermore, the PITX3 C allele carriers with PD had a poorer cognitive performance in the visuospatial domain (p < 0.001) and a higher incidence of visual hallucinations. A trend towards a lower striatal DAT uptake in the PITX3 C allele carriers was suggested, but could not be confirmed. Our results show that a common polymorphism in the PITX3 gene affects the risk of developing PDD and visuospatial dysfunction in idiopathic PD. If validated, these findings can provide new insights into the neurobiology and genetics of non-motor symptoms in PD.
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| 2. |
- Bäckström, David, et al.
(författare)
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Polymorphisms in dopamine-associated genes and cognitive decline in Parkinson's disease
- 2018
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 137:1, s. 91-98
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesCognitive decline is common in Parkinson's disease (PD), but the underlying mechanisms for this complication are incompletely understood. Genotypes affecting dopamine transmission may be of importance. This study investigates whether genotypes associated with reduced prefrontal dopaminergic tone and/or reduced dopamine D2-receptor availability (Catechol-O-methyltransferase [COMT] Val(158)Met genotype and DRD2 (CT)-T-957 genotype) affect the development of cognitive deficits in PD. Materials and methodsOne hundred and 34 patients with idiopathic PD, participating in a regional, population-based study of incident parkinsonism, underwent genotyping. After extensive baseline investigations (including imaging and biomarker analyses), the patients were followed prospectively during 6-10 years with neuropsychological evaluations, covering six cognitive domains. Cognitive decline (defined as the incidence of either Parkinson's disease mild cognitive impairment [PD-MCI] or dementia [PDD], diagnosed according to published criteria and blinded to genotype) was studied as the primary outcome. ResultsBoth genotypes affected cognition, as shown by Cox proportional hazards models. While the COMT(158)Val/Val genotype conferred an increased risk of mild cognitive impairment in patients with normal cognition at baseline (hazard ratio: 2.13, P=.023), the DRD2(957)T/T genotype conferred an overall increased risk of PD dementia (hazard ratio: 3.22, P<.001). The poorer cognitive performance in DRD2(957)T/T carriers with PD occurred mainly in episodic memory and attention. ConclusionsThe results favor the hypothesis that dopamine deficiency in PD not only relate to mild cognitive deficits in frontostriatal functions, but also to a decline in memory and attention. This could indicate that dopamine deficiency impairs a wide network of brain areas.
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