title: Genetic variation at the BDNF locus: evidence for association with long-term outcome after ischemic stroke.
abstract: OBJECTIVE
  Rates and extent of recovery after stroke vary considerably between individuals and genetic factors are thought to contribute to post-stroke outcome. Brain-derived neurotrophic factor (BDNF) plays important roles in brain plasticity and repair and has been shown to be involved in stroke severity, recovery, and outcome in animal models. Few clinical studies on BDNF genotypes in relation to ischemic stroke have been performed. The aims of the present study are therefore to investigate whether genetic variation at the BDNF locus is associated with initial stroke severity, recovery and/or short-term and long-term functional outcome after ischemic stroke.
  
  
  METHODS
  Four BDNF tagSNPs were analyzed in the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS; 600 patients and 600 controls, all aged 18-70 years). Stroke severity was assessed using the NIH Stroke Scale (NIHSS). Stroke recovery was defined as the change in NIHSS over a 3-month period. Short- and long-term functional outcome post-stroke was assessed using the modified Rankin Scale at 3 months and at 2 and 7 years after stroke, respectively.
  
  
  RESULTS
  No SNP was associated with stroke severity or recovery at 3 months and no SNP had an impact on short-term outcome. However, rs11030119 was independently associated with poor functional outcome 7-years after stroke (OR 0.66, 95% CI 0.46-0.92; P =  0.006).
  
  
  CONCLUSIONS
  BDNF gene variants were not major contributors to ischemic stroke severity, recovery, or short-term functional outcome. However, this study suggests that variants in the BDNF gene may contribute to poor long-term functional outcome after ischemic stroke.
authors.affiliation: Institute of Biomedicine, Section for Clinical Genetics, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Tara M
authors.initials: TM
authors.lastname: Stanne
authors.affiliation: Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Tjärnlund-Wolf
authors.affiliation: Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Sandra
authors.initials: S
authors.lastname: Olsson
authors.affiliation: Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Jood
authors.affiliation: Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Blomstrand
authors.affiliation: Institute of Biomedicine, Section for Clinical Genetics, the Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Jern
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D002545:Brain Ischemia / Q000150:complications; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human