RESUMEN
Introduction: The relationship between BDNF gene Val/Met polymorphism and clinical symptoms, attention and executive functions in patients with schizophrenia was investigated in this study. Also, BDNF Val66Met gene polymorphism was compared between patients and healthy controls. Thus, genetic factors that may affect both the etiology and cognitive functions in schizophrenia were evaluated. Methods: BDNF Val66Met gene polymorphism was investigated in 102 patients with schizophrenia and 98 healthy controls. Cognitive functions were evaluated by the Wisconsin Card Sorting Test (WCST) and Stroop Test. Results: There was no difference in terms of the genotypic or allelic distribution of BDNF Val66Met polymorphism between patients and healthy controls. A significantly higher percentage of suicide attempts were found in the patients having Met allele (Val/Met and Met/Met). Met allele was associated with failure in focused attention and response inhibition in patients with schizophrenia. Conclusion: The presence of the Met allele could be associated with the risk of suicide attempts in patients with schizophrenia. Impairment in executive function areas such as focused attention and response inhibition appears to be related to the Met allele.
RESUMEN
Objective: Alcohol use disorder (AUD) is a disease with chronic relapses. Risk factors of craving, which is thought to be one of the predictors of relapse, have been studied for a long time. The DRD4 gene is located on chromosome 11p and has a 48-base pair variable number of tandem repeat (VNTR) polymorphisms in the 3rd exon. This study aimed to investigate if a relationship existed between craving and DRD4 VNTR polymorphism and to determine the predictors of craving. Methods: A total of 125 patients with AUD were included in the study. The sociodemographic data form, the Michigan Alcoholism Screening Test (MAST), the Obsessive Compulsive Drinking Scale (OCDS), and the Penn Alcohol Craving Scale (PACS) were applied to the patients. Polymerase chain reaction (PCR) was used to determine the DRD4 VNTR variant of all participants in the peripheral blood sample. Results: In the 4R/4R homozygous group, it was found that the age at first alcohol use was higher and the scores of the OCDS on the seventh day were lower, but this relationship could not be demonstrated in further statistical analyses. In the stepwise linear regression model, the age at first alcohol use, MAST score, duration of AUD, and delirium tremens history were found to be the predictors of craving. Conclusion: DRD4 VNTR polymorphism does not play a role as a predictor of craving. A decrease in age at first alcohol use, an increase in the MAST score, and the presence of delirium tremens were found to be the predictors of craving among the participants of this study.