title: No association between polymorphisms in the BDNF gene and age at onset in Huntington disease.
abstract: BACKGROUND
  Recent evidence suggests that brain-derived neurotrophic factor (BDNF) is an attractive candidate for modifying age at onset (AO) in Huntington disease (HD). In particular, the functional Val66Met polymorphism appeared to exert a significant effect. Here we evaluate BDNF variability with respect to AO of HD using markers that represent the entire locus.
  
  
  METHODS
  Five selected tagging polymorphisms were genotyped across a 65 kb region comprising the BDNF gene in a well established cohort of 250 unrelated German HD patients.
  
  
  RESULTS
  Addition of BDNF genotype variations or one of the marker haplotypes to the effect of CAG repeat lengths did not affect the variance of the AO.
  
  
  CONCLUSIONS
  We were unable to verify a recently reported association between the functional Val66Met polymorphism in the BDNF gene and AO in HD. From our findings, we conclude that neither sequence variations in nor near the gene contribute significantly to the variance of AO.
authors.affiliation: Department of Human Genetics, Ruhr-University, 44780 Bochum, Germany. Maren-Mai@gmx.de
authors.forename: Maren
authors.initials: M
authors.lastname: Mai
authors.forename: Amer D
authors.initials: AD
authors.lastname: Akkad
authors.forename: Stefan
authors.initials: S
authors.lastname: Wieczorek
authors.forename: Carsten
authors.initials: C
authors.lastname: Saft
authors.forename: Jürgen
authors.initials: J
authors.lastname: Andrich
authors.forename: Peter H
authors.initials: PH
authors.lastname: Kraus
authors.forename: Jörg T
authors.initials: JT
authors.lastname: Epplen
authors.forename: Larissa
authors.initials: L
authors.lastname: Arning
mesh_terms: D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003062:Codon; D006801:Humans; D006816:Huntington Disease / Q000235:genetics*; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D018911:Trinucleotide Repeats; D014633:Valine / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D003062:Codon; D008715:Methionine; D014633:Valine