title: Association between brain-derived neurotrophic factor (BDNF) gene polymorphisms and executive function in Japanese patients with Alzheimer's disease.
abstract: BACKGROUND
  To address the functional roles of genetic polymorphisms of brain-derived neurotrophic factor (BDNF) in Alzheimer's disease (AD) from a neuropsychological aspect, we used a cross-sectional study design to investigate the association between novel single nucleotide polymorphisms (SNPs) of the BDNF gene (Val66Met (G196A) and C270T) and the Frontal Assessment Battery (FAB) score, which reflects executive function as a non-memory cognitive impairment.
  
  
  METHODS
  One hundred and sixty-nine outpatients with AD or amnestic mild cognitive impairment (A-MCI) were recruited to the study and divided into three genotypic groups for each representative BDNF functional polymorphism as follows: (i) Val66Met (G196A): G/G (n = 45), G/A (n = 104), and A/A (n = 20); and (ii) C270T: C/C (n = 160), C/T (n = 9), and T/T (n = 0). Then, age, sex ratio, duration of illness (months), education years, Mini-Mental State Examination (MMSE) score, behavioral pathology in Alzheimer disease (Behave-AD) score, Clinical Dementia Rating (CDR) ratio, and total and subtest FAB scores were compared between the genotypic groups for each SNP.
  
  
  RESULTS
  Significant differences were found in the total (P < 0.01) and subtest (conflicting instructions and prehension behavior; P < 0.01) FAB scores between the C270T polymorphism groups (C/C and C/T), but not among the G196A polymorphism groups. However, no significant differences in age, sex ratio, duration of illness (months), education years, Behave-AD score, CDR ratio, or MMSE score (reflecting attention and memory function) were found between the individual polymorphism genotypes (G196A and C270T).
  
  
  CONCLUSIONS
  Of the known BDNF polymorphisms, the C270T SNP may influence executive dysfunction as a non-memory cognitive impairment in Japanese patients with AD.
authors.affiliation: Division of Molecular Genetics, Institute of DNA Medicine, Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan. t.nagata@jikei.ac.jp
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nagata
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Shinagawa
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nukariya
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ochiai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawamura
authors.forename: Miyuki
authors.initials: M
authors.lastname: Agawa-Ohta
authors.forename: Hiroo
authors.initials: H
authors.lastname: Kasahara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakayama
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000544:Alzheimer Disease / Q000175:diagnosis / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000235:genetics*; D018450:Disease Progression; D056344:Executive Function; D005260:Female; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011110:Polymorphism, Genetic / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011594:Psychometrics; D012307:Risk Factors; D012737:Sex Factors; D013223:Statistics as Topic
chemical_list: D019208:Brain-Derived Neurotrophic Factor