title: Flanking markers of cystatin c (CST3) gene do not show association with Alzheimer's disease.
abstract: BACKGROUND
  In the present study we determined whether the cystatin c gene (CST3) is genetically associated with late-onset Alzheimer's disease (AD).
  
  
  METHODS
  Two informative flanking single nucleotide polymorphisms (SNP), rs2424577 and rs3827143, of the CST3 gene and apolipoprotein E (APOE) gene were assessed in 568 Finnish AD patients and 688 cognitively healthy controls. Samples were genotyped with the TaqMan technique, and we conducted a single allele and genotypic distribution comparison as well as an estimation of haplotype frequencies between cases and controls.
  
  
  RESULTS
  The APOE genotype distribution differed as expected between the AD cases and controls (p < 0.001). On the whole, any significant differences in AD risk were not found in single SNP and haplotype analyses for the CST3 gene between the whole study cohorts or in the stratified subgroups. Interestingly, AG-genotype carriers of rs3827143 showed a significant difference (p = 0.04) between cases and controls when compared to AA-genotype carriers, but this finding remained insignificant in the adjusted model.
  
  
  CONCLUSIONS
  Although flanking SNP cover the whole gene transcript with strong linkage disequilibrium, our data show that the CST3 gene is not associated with AD risk in the Finnish population.
authors.affiliation: Institute of Clinical Medicine, Unit of Neurology and Brain Research Unit, Clinical Research Center, Mediteknia, Kuopio University, Kuopio, Finland. seppo.helisalmi@uku.fi
authors.forename: Seppo
authors.initials: S
authors.lastname: Helisalmi
authors.forename: Antti
authors.initials: A
authors.lastname: Väkevä
authors.forename: Mikko
authors.initials: M
authors.lastname: Hiltunen
authors.forename: Hilkka
authors.initials: H
authors.lastname: Soininen
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics; D015331:Cohort Studies; D055316:Cystatin C / Q000235:genetics*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005787:Gene Frequency; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide; D018570:Risk Assessment
chemical_list: D001057:Apolipoproteins E; C525030:CST3 protein, human; D055316:Cystatin C; D005819:Genetic Markers