We used the transmission disequilibrium test (TDT) and haplotype analysis to investigate the A-161T and G861C polymorphisms in the 5-HT1B receptor gene in ADHD trios from the Chinese Han population.
Taking into account the well-known sexual dimorphic effect observed in serotonergic system characteristics, we differentially tested the influence of HTR1B SNPs (rs11568817, rs130058, rs6296 and rs13212041) on ADHD susceptibility and on its major comorbidities according to sex.
The results showed that the 861G allele of 5-HTR1B SNP rs6296 could significantly increase the risk of ADHD (C)R=1.09, 95% CI: 1.01-1.18); the 5-HTR2C gene rs518147 (OR=1.69, 95% CI: 1.38-2.07) and rs3813929 (OR = 1.57, 95% CI: 1.25-1.97) were all associated with the risk of ADHD.
We measured neural activation during stop-signal task performance in adolescents with ADHD (N = 185), their unaffected siblings (N = 111), and healthy controls (N = 124), and investigated the relationship of two serotonin gene polymorphisms (the rs6296 SNP of the HTR1B gene and HTTLPR variants of the 5-HTT gene) with the neural correlates of response inhibition.