Psychiatric genetics
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Psychiatric genetics · Jun 2007
Meta AnalysisMeta-analysis reveals no association of the Val66Met polymorphism of brain-derived neurotrophic factor with either schizophrenia or bipolar disorder.
A long-term controversy exists on whether or not major psychotic disorders can be discretely divided into two groups, for example, schizophrenia and bipolar disorder. Many genes and polymorphisms have been studied for a role in both disorders, including the Val66Met (also known as rs 6265 or G196A) variant of brain-derived neurotrophic factor (BDNF). Many case-control association studies have been performed to see if BDNF could serve as a useful clinical diagnostic biomarker for schizophrenia or bipolar disorder, but results have been equivocal. ⋯ Although there are some limitations on the study, our results indicate there is a lack of association between the Val66Met polymorphism and either of the two psychoses. A larger sample size, and evaluation of more single-nucleotide polymorphisms are needed to obtain more robust and conclusive findings regarding the relationship between the BDNF gene and psychosis.
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Psychiatric genetics · Jun 2007
The Gilles de la Tourette syndrome: a principal component factor analytic study of a large pedigree.
The genetics and phenotypes of Gilles de la Tourette syndrome are complicated. Once indicated to be inherited as a single major autosomal dominant condition, several areas of interest on many chromosomes and one gene have been identified for Gilles de la Tourette syndrome, but no results have been replicated. Factor analytic studies suggest that there are more than one Gilles de la Tourette syndrome phenotype and it is not a unitary condition. ⋯ Our results give further evidence that the genetics of Gilles de la Tourette syndrome is complex and suggest that Gilles de la Tourette syndrome is not a unitary condition, thus confirming the results of earlier studies which have described several Gilles de la Tourette syndrome phenotypes. Although a genome scan on the pedigree reported three areas of interest and the present study found three factors, further studies would have to be undertaken to elucidate whether the three factors 'mapped' with the genetic data. Possible reasons for our findings and suggestions for future research are discussed.
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Psychiatric genetics · Jun 2006
Comparative StudyCatechol-O-methyltransferase Val158Met genotype variation is associated with prefrontal-dependent task performance in schizotypal personality disorder patients and comparison groups.
A single-nucleotide polymorphism of the gene coding for catechol-O-methyltransferase (COMT Val(158)Met) is associated with prefrontal-dependent task performance in schizophrenia. We evaluated the relationship of the COMT genotype with diagnostic status and cognitive performance in schizotypal personality disorder. ⋯ (1) Allelic variation in COMT activity is unrelated to the diagnosis of SPD in this sample. (2) Individuals with SPD exhibit multiple deficits in prefrontal and temporal lobe-dependent tasks. (3) The COMT genotype is related to performance on prefrontal cortex-dependent tasks and may contribute to the deficit in prefrontal-dependent memory processes in SPD as it does in schizophrenia.
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Psychiatric genetics · Mar 2002
ReviewThe Fawn-Hooded (FH/Wjd) rat: a genetic animal model of comorbid depression and alcoholism.
The Fawn-Hooded (FH/Wjd) rat is an inbred strain of rat that has been reported to exhibit both high immobility in the forced swim test and high voluntary ethanol intake, measures that have been periodically linked with depression and alcoholism in humans. The present paper will first present a survey of the literature and previously unpublished findings that bear on the question of whether FH/Wjd rats should be considered genetic animal models of depression and alcoholism. Subsequently, behavioral studies of the FH/Wjd rats, the non-drinking ACI/N strain, and their F1 and F2 intercrosses will be described. ⋯ In addition, there were no significant litter effects, indicating that maternal effects did not appear to occur. There were also no significant differences among rats with different coat colors, suggesting that the Fawn-Hooded phenotype can be separated from the measures of alcohol intake and immobility. We conclude that the FH/Wjd rat is a genetic animal model of depression and alcoholism, but that the two measures reflective of these states are under separate genetic controls.
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Psychiatric genetics · Jun 2001
Catechol-O-methyltransferase gene polymorphism in schizophrenia: evidence for association between symptomatology and prognosis.
Catechol-O-methyltransferase (COMT) gene has long been implicated to play a role in the pathogenesis of schizophrenia. The aim of this study is to assess the relationship of schizophrenia and its subgroups with COMT gene polymorphism. We have attempted to evaluate a possible correlation between the severity and prognosis of the illness (the psychopathology of symptoms) and COMT gene polymorphisms. ⋯ However, the patients with the L/L genotype may have much more severe clinical signs in Turkish schizophrenics. COMT variations, however, do not help to evaluate the susceptibility of the patients, but can help in the estimation of severity of clinical manifestations. Further studies are required to better understand the association of symptomatology of schizophrenia and other psychiatric disorders with COMT gene polymorphism.