Genetics of suicidal behavior: Candidate association genetic approach

Suicidal behavior runs in families and seemed to be genetically determined in part and independent of the presence of psychiatric disorders. This review presents the current knowledge of candidate gene association studies in the field of suicidology. Concordance for monozygotic twins is about 13% Vs. 0.7% in dizygotics. It seems that there is a relationship to intermediate phenotypes such as impulsivity and aggression. The problem of studying complex traits and of ethnic stratification in heterogeneous population are major concerns in studying genetics of suicide. Family-based methods is one of the strategies to overcome stratification. We found a possible association of tryptophane hydroxylase gene polymorphism with depression and serotonin transporter promoter gene to violence traits by family-based methods. Recent data from the study of COMT, MAO and serotonin receptors genes polymorphisms are controversial at this stage. Future directions for research includes alternative phenotypes, endo-phenotypes and genome scan.