Association between serotonin 2A receptor genetic variations, stressful life events and suicide

Life events are series of events that disrupt a person's psychological equilibrium and may enhance the development of a disorder such as suicide. Several studies have assessed a relationship between 5-hydroxytryptamine (serotonin) 2A receptor (5-HTR2A) gene polymorphisms with an increased risk of suicide. However, there has been no study about the association between three 5-HTR2A gene polymorphisms, A1438G (rs6311), T102C (rs6313) and C1354T (rs6314), suicide, stressful life, and loss events in a same time. Relatives of 191 suicide victims were interviewed using a semi-structured questionnaire designed according to Iranian culture. Venous blood was taken from all subjects for DNA isolation. 5-HTR2A polymorphisms in a total of 191 suicide victims and 218 healthy controls were genotyped using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). Chi-squared and Fisher's exact tests were used to compare genotype and allele frequencies between suicide and control groups. Correction for multiple comparisons was calculated using Bonferroni correction. There was a significant association between the 102 C/C genotype of 5-HTR2A gene and suicide (к2 = 8.700, P = 0.012). Furthermore, we found that suicide victims with a 102 C/C genotype had a significantly higher number of stressful life and loss events (P 0.05). Our results suggest that C102T (rs6313) polymorphism of 5-HTR2A gene may be involved in the susceptibility to suicide, higher number of stressful life and loss events, but A1438G (rs6311) and C1354T (rs6314) polymorphisms of 5-HTR2A gene were not associated with suicide, higher number of stressful life and loss events. •The 102 C/C genotype of 5-HTR2A gene was associated with suicide.•Suicide victims with 102 C/C genotype had a higher number of stressful life and loss events.•There was a gene and environment (GXE) interaction between 102 C/C genotype and life events.•A1438G and C1354T of 5-HTR2A gene polymorphisms weren’t associated with suicide, stressful and loss events.