Investigation of leptin and leptin receptor gene polymorphisms in schizophrenia: further support for an association with attempted suicide

Abstract Objective: This study aimed to investigate leptin ( LEP ) (G-2548A) and leptin receptor ( LEPR ) (668A>G) gene polymorphisms in SCZ patients with and without suicide attempts, compared to controls Methods: The study included 120 patients with SCZ and 130 healthy volunteers. Sociodemographic characteristics, suicidal behavior, and symptom severity were assessed using data collection forms. Gene polymorphisms were analyzed from DNA samples using the polymerase chain reaction–restriction fragment length polymorphism. Results: The LEP genotype distribution in SCZ patients differed significantly from controls, with the heterozygous GA genotype more frequent in controls (p = .026). Within SCZ, LEPR genotype distribution differed by suicide attempt history; the heterozygous AG genotype was more frequent in non-attempters (p = .048). Logistic regression showed that the LEPR polymorphism (p = .023), number of hospitalizations (p = .036), and PANSS-psychopathology score (p = .023) predict suicide attempt history in SCZ. Conclusion: Our findings suggest that LEP polymorphism may contribute to SCZ susceptibility, while LEPR polymorphism may be linked to suicide attempts in SCZ.