The gene polymorphism of the tryptophane hydroxylase in patients with obsessive compulsive disorder

There has been limited investigations in obsessive-compulsive disorder (OCD) on the A218C polymorphism of tryptophane hydroxylase 1 (TPH 1) gene which are blamed for a variety of disesases. The aim of our study was to examine the role of TPH 1 A218C gene polymorphism on the etiology of OCD.The study composed of 60 patients who met study criteria and applied to Firat University School of Medicine Department of Psychiatry. In addition, 60 healthy age and sex matched healthy controls who met the study criteria. At the beginning of the study, Structured Clinical Interview for DSM-IV (SCID), Sociodemographical and Clinical Data Form, Yale-Brown Obsession Compulsion Scale and Hamilton Depression Rating Scale were administered. The patients were divided into two groups by their treatment history and Y-BOCS; treatment-responded and refractory patients. To examine genetically, all patients were took of 3 ml venous blood into vacuum tubes with EDTA and were stored -20°C. Three hundred µl of blood was used to isolate DNA. The method of Restriction Fragment Length Polymorphism was used to evaluate A218C polymorphism of TPH-1 gene. The statistics was performed by SPSS for Windows 12.0 statistics program.There was no difference in regard to TPH1 genotypes between groups. The frequency of A allels and that of C allels were statistically significant in treatment-responded and refractory patient groups, respectively. We suggest that allel diversities may be associated with treatment response in OCD. However, our findings required new investigations which consist of larger samples in different societies.Key Words: OCD, gene, polymorphism, tryptophane hydroxilase