Objective: To investigate the association between four serotonergic polymorphisms [A-1438G (rs6311) and T102C (rs6313) of the serotonin 2A receptor gene, and STin2 VNTR and 5-HTTLPR of the SLC6A4 gene] and suicidal behavior.
Participants and methods: One hundred and ninety-three suicide attempters (SA) and 420 unrelated healthy controls from Asturias (Northern Spain) were genotyped using standard methods.
Results: A-1438G and T102C polymorphisms were in complete linkage disequilibrium in our population. Genotype and allele distributions showed no differences between SA and control participants. In nonimpulsive suicide attempts, however, we found an excess of the -1438A allele as compared with impulsive suicide attempts and the control group [chi(2)=11.92, corrected P=0.021]. No other differences were found with regard to the impulsivity of the attempt. An excess of short allele carriers were found in the group of SA with high clinical lethality as compared with the low-lethality group [chi(1)=4.93, P=0.026, not significant after Bonferroni correction]. The haplotype analysis showed no association between suicide attempt and haplotype distribution [likelihood ratio test (5)=4.40, P=0.493].
Conclusion: Our findings suggest that the -1438A allele may predispose for nonimpulsive suicidal behavior.