title: The genotype 2/2 of the presenilin-1 polymorphism is decreased in Spanish early-onset Alzheimer's disease.
abstract: We have found a significantly lower frequency of the presenilin-1 (PS-1) intronic polymorphism 2/2 genotype in early-onset Alzheimer's disease (AD) patients without APOE epsilon4 alleles (2/2 = 0.054; P = 0.009) as compared to age matched non-epsilon4 controls (2/2 = 0.227). Moreover the average age of onset in AD patients with the PS-1 2/2 genotype is older than that in AD patients with a 1/2 genotype or with a 1/1 genotype. This data suggest a protective effect of the 2/2 genotype which would delay the age of onset in AD. Our results do not support an association between the 1/1 genotype and AD. However, a non-significant increase of the 1/1 genotype is found in non-epsilon4 AD patients (P = 0.20).
authors.affiliation: Genetics Service, Hospital Clinic i Provincial and Institut August Pi i Sunyer, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ezquerra
authors.forename: R
authors.initials: R
authors.lastname: Blesa
authors.forename: E
authors.initials: E
authors.lastname: Tolosa
authors.forename: S
authors.initials: S
authors.lastname: Lopez Pousa
authors.forename: M
authors.initials: M
authors.lastname: Aguilar
authors.forename: J
authors.initials: J
authors.lastname: Peña
authors.forename: C
authors.initials: C
authors.lastname: Van Broeckhoven
authors.forename: F
authors.initials: F
authors.lastname: Ballesta
authors.forename: R
authors.initials: R
authors.lastname: Oliva
mesh_terms: D017668:Age of Onset; D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D053764:Presenilin-1; D013030:Spain
chemical_list: D001057:Apolipoproteins E; D008565:Membrane Proteins; C508853:PSEN1 protein, human; D053764:Presenilin-1