ChromosomeGene defectAge of onsetAβ phenotype
21βAPP mutations50sProduction of total Aβ peptides or of Aβ42 peptides
19apoE4 polymorphism60s and olderDensity of Aβ plaques and vascular deposits
14Presenilin 1 mutations40s and 50sProduction of Aβ42 peptides
1Presenilin 2 mutations50sProduction of Aβ42 peptides
  • Genetic factors predisposing to Alzheimer's Disease: Relationships to the β-amyloid phenotype. Additional chromosomal loci exist but are not yet specifically identified.