title: Prion protein codon 129 genotype prevalence is altered in primary progressive aphasia.
abstract: The prion protein (PrP) is central to the prion diseases, although a role in other neurodegenerative diseases has been postulated. A common polymorphism (Met or Val) at codon 129 of the PrP gene (PRNP) features prominently in the risk and phenotype, of prion disease, and an abnormality in its distribution frequency may signal a role for PrP in other diseases. We conducted a case-control study to compare the PRNP codon 129 genotype distribution in Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and primary progressive aphasia (PPA), including 281 AD, 256 ALS, 39 PPA, and 415 healthy control subjects. Statistical analysis was applied to determine the presence or absence of disease-specific genotype associations. The distribution of codon 129 genotypes was similar among healthy control, AD, and ALS subjects, although the heterozygous state was significantly overrepresented (age-adjusted odds ratio, 8.47) in PPA, a rare condition of unknown cause. Although these findings do not entirely exclude a role for PrP in AD or ALS, they do not support the codon 129 genotype as a risk factor for either disease. However, the strong association between heterozygosity and PPA raises new questions about its cause and the role of PrP in other neurodegenerative diseases.
authors.affiliation: Department of Neurology, Pritzker School of Medicine and Center for Comprehensive Care and Research on Memory Disorders, University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637, USA.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
authors.forename: Lewis P
authors.initials: LP
authors.lastname: Rowland
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mitsumoto
authors.forename: Serge
authors.initials: S
authors.lastname: Przedborski
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bird
authors.forename: Gerard D
authors.initials: GD
authors.lastname: Schellenberg
authors.forename: Elaine
authors.initials: E
authors.lastname: Peskind
authors.forename: Nancy
authors.initials: N
authors.lastname: Johnson
authors.forename: Teepu
authors.initials: T
authors.lastname: Siddique
authors.forename: M-Marsel
authors.initials: MM
authors.lastname: Mesulam
authors.forename: Sandra
authors.initials: S
authors.lastname: Weintraub
authors.forename: James A
authors.initials: JA
authors.lastname: Mastrianni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology / Q000235:genetics; D018888:Aphasia, Primary Progressive / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D015995:Prevalence; D011328:Prions / Q000235:genetics*
chemical_list: D011328:Prions