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Updated: May 9, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
Codon 129 polymorphism of prion protein gene in is not a risk factor for Alzheimer's disease
Jerusa Smid1, Michele Christine Landemberger, Valéria Santoro Bahia
1Cognitive and Behavioral Unit, Department of Neurology, School of Medicine, USP, São Paulo SP, Brazil. jsmid@ig.com.br
Unlabelled:
Interaction of prion protein and amyloid-b oligomers has been demonstrated recently. Homozygosity at prion protein gene (PRNP) codon 129 is associated with higher risk for Creutzfeldt-Jakob disease. This polymorphism has been addressed as a possible risk factor in Alzheimer disease (AD).
Objective:
To describe the association between codon 129 polymorphisms and AD.
Methods:
We investigated the association of codon 129 polymorphism of PRNP in 99 AD patients and 111 controls, and the association between this polymorphism and cognitive performance. Other polymorphisms of PRNP and additive effect of apolipoprotein E gene (ApoE) were evaluated.
Results:
Codon 129 genotype distribution in AD 45.5% methionine (MM), 42.2% methionine valine (MV), 12.1% valine (VV); and 39.6% MM, 50.5% MV, 9.9% VV among controls (p>0.05). There were no differences of cognitive performance concerning codon 129. Stratification according to ApoE genotype did not reveal difference between groups.
Conclusion:
Codon 129 polymorphism is not a risk factor for AD in Brazilian patients.
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