Related Experiment Video
Updated: Jul 14, 2026

Developing a Rat Model for Bipolar Disorder
Published on: May 2, 2025
[Association analysis of dopamine D4 receptor gene polymorphism and attention deficit hyperactivity disorder
Li-li Guan1, Yu-feng Wang, Jun Li
1Institute of Mental Health, Peking University, Beijing 100083, China.
Objective:
To examine the role of dopamine D4 receptor gene (DRD4) in attention deficit hyperactivity disorder (ADHD) with/without disruptive behavior disorder (DBD) by focusing on a-521C/T SNP within the promoter region of this gene.
Methods:
A total of 401 DSM-IV ADHD children (including 284 trios) of Chinese Han descent were genotyped. Chi-square test and the transmission disequilibrium test (TDT) were used to test for associations in ADHD with and without DBD respectively.
Results:
In the comparison of ADHD with (n=143) and without (n=258) DBD, the -521T allele ( chi(2) = 6.778, P= 0.009, OR= 1.485) and the TT genotype (chi(2) = 6.292,P=0.012,OR=1.729) showed higher frequency in children with ADHD and DBD simultaneously. For family based analysis, T allele of the -521C/T polymorphism was preferentially transmitted to ADHD children with comorbid DBD (n=100, chi(2) = 3.868,P=0.049), whereas no significant distortion was found in the transmission of the tested variant for ADHD without DBD (n=184, chi(2) = 0.223, P=0.637).
Conclusion:
Our findings suggest that the -521C/T SNP of DRD4 may contribute to the predisposition to ADHD with comorbid DBD. This study supports for the hypothesis that ADHD with comorbid DBD may be influenced by greater genetic effect compared to ADHD alone.
Related Concept Videos
Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Behavioral Genetics and Its Designs
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Oppositional Defiant Disorder
Diagnostic Criteria and...
Drugs Affecting Neurotransmitter Synthesis

