title: [Risk of attention deficit/hyperactivity disorder in Aymara and Rapa-Nui school children: association with dopaminergic system polymorphisms].
abstract: BACKGROUND
  Attention deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness or inattentiveness.
  
  
  OBJECTIVE
  To search for differences in risk for ADHD and its components among Chilean native and mixed populations and to look forpossible associations with dopamine receptor D4 (DRD4) and dopamine transporter 1 (DAT1) polymorphisms.
  
  
  METHODS
  School teachers were requested to complete the Conners test, which uses DSM-IV criteria, to screen for ADHD risk among Aymara and Rapa-Nui students.
  
  
  RESULTS
  Rapa-Nui children from Easter Island had the highest risk of hyperactivity/impulsiveness. Aymara children from the Arica-Parinacota Region had lower scores. Although inattentiveness scores had lower differences between groups, overall ADHD score differences among studied populations were highly significant. DRD4 and DAT1 alleles had a heterogeneous distribution. Easter islanders had more divergent frequencies, mostprobably as a result of separate migration routes utilized at different timeperiods during the colonization of America and Polynesia.
  
  
  CONCLUSIONS
  The comparison of ADHD risk parameters between Rapa-Nui and Aymara children showed marked differences. Allele distri-bution of dopamine polymorphisms in Easter Island was also significantly different from northern Chile, due probably to different colonization histories. These findings suggest that higher ADHD risk scores in Easter Island children may be linked to the presence of different DRD4 alleles.
authors: Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile.
authors: Liza
authors: L
authors: Paz Lagos
authors: Claudio
authors: C
authors: Silva
authors: Paula
authors: P
authors: Rothhammer
authors: Ximena
authors: X
authors: Carrasco
authors: Elena
authors: E
authors: Llop
authors: Francisco
authors: F
authors: Aboitiz
authors: Francisco
authors: F
authors: Rothhammer
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002677:Chile / Q000208:ethnology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics*; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012307:Risk Factors
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D050638:Receptors, Dopamine D4