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Lack of influence of COMT and NET genes variants on executive functions in schizophrenic and bipolar patients, their first‐degree relatives and controls
Author(s) -
Szöke A.,
Schürhoff F.,
Méary A.,
Mathieu F.,
Chevalier F.,
Trandafir A.,
Alter C.,
Roy I.,
Bellivier F.,
Leboyer M.
Publication year - 2006
Publication title -
american journal of medical genetics part b: neuropsychiatric genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.393
H-Index - 126
eISSN - 1552-485X
pISSN - 1552-4841
DOI - 10.1002/ajmg.b.30352
Subject(s) - bipolar disorder , wisconsin card sorting test , psychology , rs4680 , confounding , schizophrenia (object oriented programming) , prefrontal cortex , catechol o methyl transferase , genotype , dopamine , dopaminergic , clinical psychology , medicine , psychiatry , cognition , gene , genetics , neuroscience , biology , neuropsychology
Abnormal dopaminergic function in the prefrontal cortex (PFC) may be a key factor in the etiopathogeny of schizophrenia and bipolar disorder. Both schizophrenic and bipolar subjects have executive functions (EF) deficits, thought to reflect abnormal PFC function. The main inactivation pathways for dopamine in the PFC are enzymatic cleavage by the Carboxy‐O‐Methyl‐Transferase (COMT) and reuptake by the nor‐epinephrine transporter (NET). Our aim in this study was to replicate previous studies that investigated influence of the COMT genotype on EF in schizophrenic subjects, their relatives and controls and extend their scope by including bipolar patients, and their relatives and by exploring NET gene polymorphisms influence on executive performances. We investigated one functional polymorphism of the COMT gene and two polymorphisms of the NET gene. EF were assessed by means of the Trail Making Test (TMT) and the Wisconsin Card Sorting Test (WCST). We assessed the effect of each of the three genotypes on EF for the whole sample (N = 318) and separately in schizophrenic (N = 66), bipolar (N = 94) and healthy subjects (i.e., relatives and controls N = 158). Separate analyses were performed because of the presence, in patients samples, of potentially confounding factors, especially medication. Genotype had no significant effect on the cognitive measures in any of the analyses (for the two EF measures, the three polymorphisms, and the four groups). In our sample we found no evidence in favor of a major effect of COMT or NET polymorphisms on the two tests of EF. © 2006 Wiley‐Liss, Inc.