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). Genotype and allele distributions of A1438G (rs6311) and C1354T (rs6314) polymorphisms of 5-HTR2A gene showed no differences between suicide victims and control participants and there was no association between genotype distribution and 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.