A pilot study of early onset obsessive-compulsive disorder: Symptom dimensions and association analysis with polymorphisms of the serotonin transporter gene

Our aim was to introduce more homogenous phenotypes for studying genetic variations in the clinically heterogeneous obsessive compulsive disorder (OCD) beside classical case-control analysis. Symptoms were assessed with Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), and principle component analysis of the lifetime symptom categories yielded four factors (Cleaning, Obsessive, Compulsive, Sexual). The comparison of serotonin transporter linked polymorphic region (5-HTTLPR) in 102 OCD patients and 223 controls showed an increased L-allele frequency but no difference was observed when rs25531 was included. Intronic variants of the serotonin transporter gene did not show association with either OCD, nor with the obtained factors.