Building: Bourbon Cataratas Convention Centre, Foz do Iguaçu
Room: Iguazu II
Date: 2014-05-05 03:30 PM – 03:45 PM
Last modified: 2014-02-09
Abstract
Introduction
Attention Deficit and Hyperactivity Disorder (ADHD) is a common condition of childhood characterized by symptoms of inattention, hyperactivity and/or impulsivity. Candidate genes involved in dopaminergic and serotoninergic pathways and neuroplasticity have been proposed for the etiological study of ADHD.
Methods
DSM IV checklist and Multidimensional Behavior Assessment System for Children (BASC) criteria were applied to 250 children to evaluate the presence of ADHD. 117 cases and 80 controls were selected. DNA from blood samples was obtained from all cases and control and 86 trios (case and his/her parents). Subsequent PCR, PCR-RFLP or STR analysis were performed to genotype eight polymorphisms located in seven genes (DRD4, DRD5, DAT1, DBH, HTR1B, 5HTT and SNAP25). A Transmission Disequilibrium Test (TDT) and a case-control analysis were used to evaluate possible association to ADHD.
Results
TDT analysis did not show evidence of preferential allelic transmission in any of the studied polymorphisms. Case-control study identified an association between ADHD and the genotype of T1065G and T1069C variants located in SNAP25 gene (p=0.0025 and p=0.009). Also there was an association of ADHD to the haplotype of these variants. An endophenotype analysis showed a correlation between the genotype of a variable number tandem repeat (VNTR) located in DAT1 gene and subtests of cognitive flexibility (p≤ 0.01) and processing speed index (p<0.05) deficit.
Conclusions
SNAP25 gene is associated to ADHD susceptibility. Endophenotype studies in highly heterogeneous disorders can be useful in the identification of susceptibility factors such as DAT1 gene in ADHD.
Keywords
References
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