Epistatic effect of APP717 mutation and apolipoprotein E genotype in familial Alzheimer's disease.
We found a new familial Alzheimer's disease kindred in which the disease cosegregates with the APP717Val-->Ile mutation and in which all of the three most common apolipoprotein E (ApoE) alleles are represented. We studied the relationship between ApoE genotype and the clinical expression of the disease and found that in this amyloid precursor protein-mutated family, ApoE genotype influences the age at onset of the disease. Three mutated subjects heterozygous for the epsilon 4 allele had the earliest age at onset in this family, subjects heterozygous for the epsilon 2 allele had the latest age at onset, and subjects homozygous for the epsilon 3 allele had an intermediate age at onset. In this large kindred we also found an amyloid precursor protein-mutated subject 2.4 standard deviations older than the mean age at onset without clinical signs and symptoms of the disease and carrying the epsilon 2/epsilon 3 genotype.
Sorbi
S
S
Department of Neurological and Psychiatric Sciences, University of Florence, Italy.
Nacmias
B
B
Forleo
P
P
Piacentini
S
S
Latorraca
S
S
Amaducci
L
L
D000328:Adult; D000544:Alzheimer Disease / Q000235:genetics*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics*; D001483:Base Sequence; D004843:Epistasis, Genetic; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree
C094559:APP717; D016564:Amyloid beta-Protein Precursor; D001057:Apolipoproteins E