Lack of association between the insertion/deletion polymorphism in the serotonin transporter gene and schizophrenia]

The authors analyzed the association between polymorphism of serotonin transporter gene and schizophrenia. This polymorphism is characterised by a 44-bp insertion or deletion in the promoter region of the gene which influences its transcriptional activity.349 not related patients with paranoid schizophrenia were included in this study. Using the SCID (Structured Clinical Interview for DSM-IV Axis I Disorders) a consensus diagnosis, according to the DSM-IV criteria was made by two independent psychiatrists for each patient. The control group consisted of 372 persons who have not been examined by psychiatrists. Genomic DNA was extracted from whole blood leukocytes using a salting out method. The polymorphism was amplified by the polymerase chain reaction (PCR). We received two products of PCR: 406 base pairs (short allele) and 450 base pairs (long allele).We analyzed genotypes and alleles of the 5-HTTLPR polymorphism in the group of patients and in the control group. We also divided our sample according to their gender and early onset of schizophrenia. The analysis did not show any significant differences between the studied groups.In the present study no association between 5-HTTLPR polymorphism and schizophrenia was found.