Introduction: ADHD has a strong genetic component. The dopamine transporter gene (DAT1) has beenassociated with susceptibility to ADHD and its endophenotypes. 40pb VNTR region in the 3`UTR ofDAT1 increases its expression. In Colombia there are no previous studies showing evidence of geneticassociation between ADHD and DAT1 gene. Objective: To determine the association between theDAT1 VNTR and the phenotype and / or endophenotypes of ADHD. Methods: We selected 73 patientswith ADHD and 75 controls. Cases were assessed for intelligence and executive functions. The VNTRin DAT1 was PCR-amplified. Population genetic and statistical analyses were performed. Logisticregression between genotype and neuropsychological testing was run. Results: The DAT1polymorphism was not associated with ADHD, or disturbances in executive functions. The 10/10genotype of the DAT1 VNTR was associated with the processing speed index (p < 0. 05). In patientswith hyperactivity subgroup the genotype was associated to some subtests of cognitive flexibility, number of correct responses, total errors and perseverative response rate (p ≤ 0. 01). In mixed subgroupit was associated with verbal comprehension index (p < 0. 05). Conclusions: There was no associationbetween the VNTR polymorphism of DAT1 and ADHD. Associations were found between genotypeand some test of cognitive flexibility and verbal comprehension index. Population genetic statistics ofthis genetic polymorphism were established for the study population, which corresponds to the firstreport in our country.
publication date
2013-02-05
Research
keywords
DAT1
VNTR
attention deficit disorder and hyperactivity disorder (ADHD)
