title: Investigation of Genetic Variants Associated with Alzheimer Disease in Parkinson Disease Cognition.
abstract: BACKGROUND
  Meta-analysis of genome-wide association studies have implicated multiple single nucleotide polymorphisms (SNPs) and associated genes with Alzheimer disease. The role of these SNPs in cognitive impairment in Parkinson disease (PD) remains incompletely evaluated.
  
  
  OBJECTIVE
  The objective of this study was to test alleles associated with risk of Alzheimer disease for association with cognitive impairment in Parkinson disease (PD).
  
  
  METHODS
  Two datasets with PD subjects accessed through the NIH database of Genotypes and Phenotypes contained both single nucleotide polymorphism (SNP) arrays and mini-mental state exam (MMSE) scores. Genetic data underwent rigorous quality control and we selected SNPs for genes associated with AD other than APOE. We constructed logistic regression and ordinal regression models, adjusted for sex, age at MMSE, and duration of PD, to assess the association between selected SNPs and MMSE score.
  
  
  RESULTS
  In one dataset, PICALM rs3851179 was associated with cognitive impairment (MMSE <  24) in PD subjects > 70 years old (OR = 2.3; adjusted p-value = 0.017; n = 250) but not in PD subjects ≤ 70 years old.
  
  
  CONCLUSIONS
  Our finding suggests that PICALM rs3851179 could contribute to cognitive impairment in older patients with PD. It is important that future studies consider the interaction of age and genetic risk factors in the development of cognitive impairment in PD.
authors.affiliation: Department of Neurology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Barrett
authors.affiliation: Bioinformatics Core, University of Virginia School of Medicine, Charlottesville, VA, USA.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Koeppel
authors.affiliation: Department of Neurology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Flanigan
authors.affiliation: Bioinformatics Core, University of Virginia School of Medicine, Charlottesville, VA, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Turner
authors.affiliation: Department of Neurology, University of Virginia, Charlottesville, VA, USA.|Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA.
authors.forename: Bradford B
authors.initials: BB
authors.lastname: Worrall
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000209:etiology* / Q000235:genetics*; D003071:Cognition; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D034041:Monomeric Clathrin Assembly Proteins / Q000235:genetics*; D010300:Parkinson Disease / Q000150:complications* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D034041:Monomeric Clathrin Assembly Proteins; C439003:PICALM protein, human
keywords: Alzheimer disease; Parkinson disease; dementia; genetics; mild cognitive impairment