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.