The Association of COMT Gene Polymorphism and Tourette Syndrome: A Family Based and Case Control Study

ABSTRACT

OBJECTIVES: Tourette disorder is known to be a disease with a strong genetic trait. There has been some recent research on the relationship between the allelic frequency distribution and Tourette disorder. In Korea, the relationship between the genetic type and the alleles for the COMT gene has been studied in Tourette patients. METHODS: Seventy two patients who were diagnosed with Tourette disorder according to the DSM-IV diagnostic criteria were selected for this study. The diagnosis and clinical features were confirmed by the Yale Global Tic Severity Scale. For the control group, the parents of the patients were chosen. Blood samples were taken from the 289 subjects. DNA was extracted from the blood lymphocytes and PCR was performed for assessing COMT gene. RESULTS: On comparing the Tourette disorder transmitted group and the not-transmitted group, no significant difference was seen between the COMT genetic type and the allelic distribution. CONCLUSION: Even though this result is viewed that there is no relationship between Tourette disorder and the COMT gene, it is difficult to firmly accept this negative result. Follow up studies with a larger patient population or pure subgroups are expected in the future.