ABSTRACT
Dementia is a common complication of Parkinson's disease (PD). It correlates significantly with the presence of cortical, limbic or nigral Lewy bodies, mainly constituted of alpha-synuclein. Mutations of the alpha-synuclein gene (SNCA) have been linked to rare familial forms of PD, while association studies on the promoter polymorphisms have given conflicting results in sporadic patients. We have performed a case control study to investigate whether genetic variability in the promoter of the alpha-synuclein gene could predispose to dementia in PD. A total of 114 demented patients and 114 non-demented patients with sporadic PD were included in the study. Six polymorphic loci (including the Rep1 microsatellite) in the promoter of the SNCA gene were examined. Each marker, taken individually, did not show association to dementia and no significant differences were observed in the inferred haplotype frequencies of demented and non-demented patients. Our data suggest the lack of involvement of the SNCA promoter in the pathogenesis of dementia in PD. Further studies in other populations are needed to confirm these results.
Subject(s)
Dementia/genetics , Haplotypes , Parkinson Disease/genetics , Promoter Regions, Genetic , alpha-Synuclein/genetics , Aged , Female , Humans , Male , Middle Aged , Polymorphism, GeneticSubject(s)
Gene Dosage , Nerve Tissue Proteins/genetics , Spinocerebellar Ataxias/genetics , Adult , Age of Onset , Aged , Alleles , Ataxins , Family Health , Female , Genes, Dominant , Humans , Male , Middle Aged , Nucleotides/genetics , PedigreeSubject(s)
Parkinson Disease/genetics , Point Mutation , Protein Serine-Threonine Kinases/genetics , Adult , Age of Onset , Aged , Aged, 80 and over , Case-Control Studies , Female , Genes, Dominant , Haplotypes , Heterozygote , Humans , Italy , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 , Male , Middle AgedABSTRACT
Contradictory evidence has been reported on the role of the polymorphic mixed dinucleotide repeat (NACP-REP1) of the alpha-synuclein gene as a risk factor for sporadic Parkinson's disease (PD). In the present study we genotyped the NACP-REP1 polymorphism in 189 PD patients from southern Italy and 182 healthy control subjects. We failed to demonstrate an association of any NACP-REP1 allele with PD.
