Catechol-O-methyltransferase and Gilles de la Tourette syndrome

Gilles de la Tourette syndrome (TS) is a neuropsychiatric disorder characte rized by both motor and vocal ties. Individuals with TS often have symptoms of obsessive compulsive disorder (OCD) and these symptoms are thought to b e an alternative expression of the TS gene(s) in TS families. In this paper we test for link age of the functional polymorphism in the catechol-O-meth yltransferase (COMT) gene to TS and OCD in five multi-generational families ascertained through a TS proband. This polymorphism (valine to methionine at codon 158) has been previously reported to influence the activity of COM T by three to four-fold and has recently been reported to be associated wit h OCD.(1) We tested for linkage using an autosomal dominant model with redu ced penetrance and non-parametric methods. No significant evidence for link age was found for the COMT gene and the TS/CMT, or OCD phenotypes in these pedigrees.