%0 Journal Article
%T Frequency Distribution of COMT Polymorphisms in Greek Patients with Schizophrenia and Controls: A Study of SNPs rs737865, rs4680, and rs165599
%A Kotrotsou Maria
%A Touloumis Charalampos
%A Dido Vassilakopoulou
%A Syriou Stavroula
%A Kalampoki Vasiliki
%A Drakoulis Nikolaos
%J ISRN Psychiatry
%D 2012
%R 10.5402/2012/651613
%X Schizophrenia, a severe psychiatric condition, is characterized by disturbances of cognition, emotion, and social functioning. The disease affects almost 1% of world population. Recent studies evaluating the role of catechol-O-methyltransferase enzyme (COMT) polymorphisms in the pathogenesis of schizophrenia have resulted in ambiguous findings. The current study examined the association of schizophrenia with three COMT polymorphisms, namely, rs737865, rs4680, and rs165599 in a Greek population. There was no significant association between schizophrenia and any of the three SNPs examined. However, haplotype analysis showed that cases have higher frequency of the T-A-A haplotype, and participants with that haplotype were at increased risk for developing schizophrenia (OR = 1.52; CL£¿:£¿1.12¨C2.08; ). Furthermore, patients with schizophrenia displayed an excess of TC/AA/AA and the TT/AA/GA genotypes. Similarly a protective effect of TT/GG/GG and TT/GA/GG was suggested by our results. 1. Background Schizophrenia is a severe, particularly devastating, psychiatric disorder affecting approximately 1% of the general population [1]. The disease is accompanied by significant social dysfunction. The onset of the symptoms usually occurs in young adulthood. Even though schizophrenia is highly heritable, the research for chromosomal loci and candidate genes has not provided any consistent results. Combinations of genetic, epigenetic, and environmental factors participate in the development of the disease. Since these factors have not been identified, the diagnosis of schizophrenia is based on phenotypic symptoms only [2]. Therefore, the identification of susceptibility genes is likely to provide valuable insights into the etiology and pathogenesis of the disease, consequently leading to the development of more effective treatments. Catechol-O-methyltransferase (COMT) is an enzyme, which catalyses the O-methylation of catecholamine neurotransmitters such as dopamine, adrenaline, and noradrenaline [3]. Disturbances in dopaminergic transmission have long been implicated in schizophrenia [4]. A ¡°reformulated¡± hypothesis of the dopamine¡¯s role in the disease states that hyperdopaminergic functioning in subcortical structures is associated with positive symptoms such as hallucinations and delusions, whereas hypodopaminergic functioning in prefrontal cortical regions is associated with negative and cognitive symptoms [5]. Dopamine is inactivated either by reuptake into the neurons that release dopamine into the synapse or through metabolism by monoamine oxidase or COMT. In
%U http://www.hindawi.com/journals/isrn.psychiatry/2012/651613/