Polymorphism in the tyrosine hydroxylase (TH) gene is associated with activity-impulsivity in German Shepherd Dogs

PLoS One. 2012;7(1):e30271. doi: 10.1371/journal.pone.0030271. Epub 2012 Jan 17.


We investigated the association between repeat polymorphism in intron 4 of the tyrosine hydroxylase (TH) gene and two personality traits, activity-impulsivity and inattention, in German Shepherd Dogs. The behaviour of 104 dogs was characterized by two instruments: (1) the previously validated Dog-Attention Deficit Hyperactivity Disorder Rating Scale (Dog-ADHD RS) filled in by the dog owners and (2) the newly developed Activity-impulsivity Behavioural Scale (AIBS) containing four subtests, scored by the experimenters. Internal consistency, inter-observer reliability, test-retest reliability and convergent validity were demonstrated for AIBS. Dogs possessing at least one short allele were proved to be more active-impulsive by both instruments, compared to dogs carrying two copies of the long allele (activity-impulsivity scale of Dog-ADHD RS: p = 0.007; AIBS: p = 0.023). The results have some potential to support human studies; however, further research should reveal the molecular function of the TH gene variants, and look for the effect in more breeds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Attention Deficit Disorder with Hyperactivity / diagnosis
  • Attention Deficit Disorder with Hyperactivity / genetics*
  • Attention Deficit Disorder with Hyperactivity / physiopathology
  • Diagnostic and Statistical Manual of Mental Disorders
  • Dog Diseases / diagnosis
  • Dog Diseases / genetics*
  • Dog Diseases / physiopathology
  • Dogs
  • Female
  • Gene Frequency
  • Genetic Association Studies / methods
  • Genotype
  • Humans
  • Impulsive Behavior / diagnosis
  • Impulsive Behavior / genetics*
  • Impulsive Behavior / physiopathology
  • Introns / genetics
  • Male
  • Middle Aged
  • Motor Activity / genetics
  • Motor Activity / physiology
  • Ownership
  • Pets
  • Phenotype
  • Polymorphism, Genetic*
  • Psychiatric Status Rating Scales / standards
  • Tyrosine 3-Monooxygenase / genetics*
  • Young Adult


  • Tyrosine 3-Monooxygenase