Genetic findings of obsessive-compulsive disorder; [Obsesif-kompulsif bozuklukta genetik çalişmalar]
Abstract
Obsessive-compulsive disorder (OCD) is characterized by repetitive, intrusive ideations, image or urges (obsession] and/or rigid, ritualistic and time-consuming behaviours (compulsions). Early evidences on inheritance of OCD have been obtained from family and twin studies. Segregation analysis provides basic support for existence of a major gene locus. In only published linkage analysis, it was reported that multipoint linkage was found on chromosome 9p. Recently, genetic studies have centered on plausible candidate genes, which are thought to be involved in the etiology of OCD. Preliminary findings from the studies of several candidate genes have contributed to previous clinical findings, especially related to serotonergic and dopaminergic systems. Also, the candidate genes of opioid, glutamatergic systems as well as the genes of immune system and neurodevelopmental progress give hope to researchers for future investigation of these systems. In this review, the family, twin, segregation, linkage, and candidate genes studies of OCD will be reviewed.