PCLO gene: Its role in vulnerability to major depressive disorder.

BACKGROUND: A recent genome-wide association study on Major Depressive Disorder (MDD) identified a specific association with a non-synonymous polymorphism (rs2522833) of a gene encoding the presynaptic protein piccolo (PCLO). A high percentage of patients who develop MDD have particular temperamental traits, such as passivity, pessimism, indecisiveness, and low self-esteem, which are related to the subsequent development of depression. The aims of this study were to perform a replicate case-control study and to conduct the first association study between the rs2522833 polymorphism and depression-related personality traits using the Temperament and Character Inventory (TCI) in a healthy subject sample. METHODS: A total of 522 MDD patients and 375 healthy volunteers were enrolled in the study. Two hundred and forty-six controls agreed to fill out the TCI. RESULTS: The results showed that rs2522833 CC homozygotes were more frequent among the depressed patients than in the controls (p