Background: Suicide attempts and deliberate self-poisoning represent a major public health and forensic concern worldwide. Emerging evidence suggests a significant genetic predisposition influencing suicidal behavior through altered neurotransmission and neuroplasticity. To date, there are scarce studies on the association of gene polymorphism and suicidal poisoning. This study aimed to investigate the distribution of genetic variants in 5-HTTLPR, BDNF rs6265, BDNF rs10835210, and SAT1 in suicide attempters and non-suicide poisoning cases in order to evaluate their potential as diagnostic markers and predictors of lethality. Methods: This observational cross-sectional study was performed on 460 adult patients diagnosed with acute poisoning at Benha Poisoning Treatment and Toxicology Research Unit (BPTTRU), Benha University Hospital, from August 2024 to July 2025. The patients were divided into two groups: the suicidal group and the non-suicidal group. Evaluation included medical history, vital signs, conscious state, general and systemic examination, necessary investigations, clinical outcome, and genotyping that was performed using the PCR-RFLP method. Results: Genotypes and alleles of studied genes showed significant differences (P = 0.001) between suicidal and non-suicidal groups, except BDNF rs6265 allele frequencies didn’t show significant (P = 0.447) differences between the two groups. The 5-HTTLPR SS genotype (OR = 4.94) and the BDNF rs6265 AG genotype (OR = 1.85) were all significantly associated with an increased tendency for suicide. Conversely, the SAT1 "I" genotype served as a significant protective factor associated with lower odds of suicide. As regards the fatality of suicidal poisoning attempts, survival and death cases showed a highly statistically significant difference regarding the HTTLPR, BDNFrs6265, BDNFrs10835210, and SSAT genotypes (P < 0.001) and the 5-HTTLPR SS genotype, BDNF rs6265 AG, and rs10835210. AC variants showed massive increases in the odds of fatal outcomes. Conclusion: Specific alleles and genotypes of 5-HTTLPR, BDNF, and SAT1 are significantly associated with suicidal poisoning and fatal outcomes, indicating that these genetic markers may be combined with clinical risk factors, including psychiatric history, type of poisoning, and severity grading, as diagnostic instruments for suicidal death. |
