title: Early-onset Alzheimer's disease in two Iranian families: a genetic study.
abstract: BACKGROUND
  Early-onset Alzheimer's disease (EOAD) represents less than 5% of all AD cases. Autosomal dominant EOAD has been defined as the occurrence of at least three cases in three generations. Mutations in the amyloid precursor protein (APP), presenilin-1 and presenilin-2 genes have been recognized to be the cause of EOAD.
  
  
  OBJECTIVE
  We investigated the genotype of EOAD in two generations of two families with EOAD living in an Iranian village.
  
  
  METHODS
  The polymerase chain reaction method was used to study the presenilin-1 and APP genes in 25 subjects of these generations.
  
  
  RESULTS
  A guanine-to-adenine transition in exon 17 of the APP gene resulting in a valine-to-isoleucine substitution at codon 717 was detected in 14 subjects including 6 patients with EOAD.
  
  
  CONCLUSIONS
  This mutation demonstrates the importance of γ-secretase, the necessity of early detection of patients with memory decline in the susceptible population and raising public awareness of consanguinity marriages.
authors.affiliation: Memory and Behavioral Neurology Department (MBND), Roozbeh Hospital, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Noroozian
authors.forename: Parisa
authors.initials: P
authors.lastname: Azadfar
authors.forename: Leila
authors.initials: L
authors.lastname: Akbari
authors.forename: Arghavan
authors.initials: A
authors.lastname: Sadeghi
authors.forename: Massoud
authors.initials: M
authors.lastname: Houshmand
authors.forename: Nasim
authors.initials: N
authors.lastname: Vousooghi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zarrindast
authors.forename: Alireza
authors.initials: A
authors.lastname: Minagar
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology; D019943:Amino Acid Substitution; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D042241:Early Diagnosis; D005091:Exons; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D053764:Presenilin-1 / Q000235:genetics*; D053766:Presenilin-2 / Q000235:genetics; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; C508853:PSEN1 protein, human; C508861:PSEN2 protein, human; D053764:Presenilin-1; D053766:Presenilin-2