Determining Expression Profile of Leucine-Rich Repeating Transmembrane Protein4 (LRRTM4) In Suicide Cases

Objective: Suicide is important in forensic medicine. Studies conducted to determine the etiology of suicide have shown that genetic factors have a critical role along with neuroendocrine changes occurring in the brain. It has been shown that dysregulation in the glutamatergic signaling pathway plays an essential role. One of the glutamatergic genes that causes suicide is the leucine-rich repeating transmembrane protein4 (LRRTM4). In our study, unlike previous studies, we planned to investigate LRRTM4 gene expression levels at mRNA and protein levels by taking samples from the dorsolateral prefrontal cortex (DLPFC) of the brain from autopsy cases. It was aimed to determine whether there is a statistically significant difference in LRRTM4 gene expression levels between suicide and non-suicide cases. Methods: The study group consisted of 38 suicides. The control group consisted of 30 non-suicidal cases. Samples were taken from the DLPFC in the brain from these cases at autopsy. In the tissue samples obtained LRRTM4 gene expressions were analyzed at the mRNA and protein level using quantitative PCR and western blot methods. Results: LRRTM4 gene expression values of suicides and non-suicide cases were compared. It was found to be 1.6 times higher in the study group than in the control group. Conclusion: It has been determined that there is a statistically significant positive relationship between suicide and the LRRTM4. Our findings will contribute positively to the pre-detection of risk factors in suicidal individuals and the medicolegal evaluation. Furthermore, our study will guide further research on the role of genetic factors in the etiology of suicide.