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| 2. |
- Hibar, Derrek P., et al.
(författare)
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Novel genetic loci associated with hippocampal volume
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 3. |
- Jonsson, Erik G., et al.
(författare)
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DTNBP1, NRG1, DAOA, DAO and GRM3 Polymorphisms and Schizophrenia : An Association Study
- 2009
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Ingår i: Neuropsychobiology. - : S. Karger AG. - 0302-282X .- 1423-0224. ; 59:3, s. 142-150
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Tidskriftsartikel (refereegranskat)abstract
- Background: Several studies of the dystrobrevin-binding protein 1 gene (DTNBP1), neuregulin 1 (NRG1), D-amino-acid oxidase (DAO), DAO activator (DAOA, G72), and metabotropic glutamate receptor 3 (GRM3) genes have suggested an association between variants of these genes and schizophrenia. Methods: In a replication attempt, single-nucleotide polymorphisms of the DTNBP1, NRG1, DAO, DAOA, and GRM3 genes were analyzed in three independent Scandinavian schizophrenia case-control samples. Results: One DTNBP1 and three GRM3 single-nucleotide polymorphisms showed nominal significant associations to the disease. However, after correction for multiple testing, there were no statistically significant allele, genotype or haplotype case-control differences. Conclusions: The present Scandinavian results do not verify previous associations between the analyzed DTNBP1, NRG1, DAO, DAOA, and GRM3 gene polymorphisms and schizophrenia. Additional studies and meta-analyses are warranted to shed further light on these relationships. Copyright (C) 2009 S. Karger AG, Basel
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| 4. |
- Kaufmann, Tobias, et al.
(författare)
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Common brain disorders are associated with heritable patterns of apparent aging of the brain
- 2019
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Ingår i: Nature Neuroscience. - : Nature Publishing Group. - 1097-6256 .- 1546-1726. ; 22:10, s. 1617-
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Tidskriftsartikel (refereegranskat)abstract
- Common risk factors for psychiatric and other brain disorders are likely to converge on biological pathways influencing the development and maintenance of brain structure and function across life. Using structural MRI data from 45,615 individuals aged 3-96 years, we demonstrate distinct patterns of apparent brain aging in several brain disorders and reveal genetic pleiotropy between apparent brain aging in healthy individuals and common brain disorders.
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| 5. |
- Saetre, Peter, et al.
(författare)
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The Tryptophan Hydroxylase 1 (TPH1) Gene, Schizophrenia Susceptibility, and Suicidal Behavior : A Multi-Centre Case-Control Study and Meta-Analysis
- 2010
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Ingår i: American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics. - : Wiley. - 1552-4841. ; 153B:2, s. 387-396
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Tidskriftsartikel (refereegranskat)abstract
- Serotonin (5-hydroxytryptamin; 5-HT) alternations has since long been suspected in the pathophysiology of schizophrenia. Tryptophan hydroxylase (tryptophan 5-monooxygenase; TPH) is the rate-limiting enzyme in the biosynthesis of 5-HT, and sequence variation in intron 6 of the TPH1 gene has been associated with schizophrenia. The minor allele (A) of this polymorphism (A218C) is also more frequent in patients who have attempted suicide and individuals who died by suicide, than in healthy control individuals. In an attempt to replicate previous findings, five single nucleotide polymorphisms (SNPs) were genotyped in 837 Scandinavian schizophrenia patients and 1,473 controls. Three SNPs spanning intron 6 and 7, including the A218C and A779C polymorphisms, were associated with schizophrenia susceptibility (P = 0.019). However there were no differences in allele frequencies of these loci between affected individuals having attempted suicide at least once and patients with no history of suicide attempts (P=0.84). A systematic literature review and meta-analysis support the A218C polymorphism as a susceptibility locus for schizophrenia (odds ratio 1.17, 95% confidence interval 1.07-1.29). Association studies on suicide attempts are however conflicting (heterogeneity index I-2 = 0.54) and do not support the A218C/A779C polymorphisms being a susceptibility locus for suicidal behavior among individuals diagnosed with a psychiatric disorder (OR = 0.96 [0.80-1.16]). We conclude that the TPH1 A218/A779 locus increases the susceptibility of schizophrenia in Caucasian and Asian populations. In addition, the data at hand suggest that the locus contributes to the liability of psychiatric disorders characterized by elevated suicidal rates, rather than affecting suicidal behavior of individuals suffering from a psychiatric disorder.
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| 6. |
- Satizabal, Claudia L., et al.
(författare)
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Genetic architecture of subcortical brain structures in 38,851 individuals
- 2019
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 51:11, s. 1624-
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Tidskriftsartikel (refereegranskat)abstract
- Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease.
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| 7. |
- Vares, Maria, et al.
(författare)
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Association Between Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Age of Onset in Schizophrenia
- 2010
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Ingår i: American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics. - : Wiley. - 1552-4841. ; 153B:2, s. 610-618
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Tidskriftsartikel (refereegranskat)abstract
- Different lines of evidence indicate that methylenetetrahydrofolate reductase (MTHFR) functional gene polymorphisms, causative in aberrant folate-homocysteine metabolism, are associated with increased vulnerability to several heritable developmental disorders. Opposing views are expressed considering the possible association between MTHFR and susceptibility for schizophrenia. In order to evaluate if age of onset could explain some of this discrepancy we investigated the relationship between two functional MTHFR gene polymorphisms and age at onset in this disorder. Scandinavian patients (n = 820) diagnosed with schizophrenia, schizoaffective disorder, and schizophreniform disorder were investigated. Two functional MTHFR single nucleotide polymorphisms (SNPs; rs1801131 and rs1801133) were genotyped and the effect of MTHFR polymorphisms on the age of onset was examined with survival analysis. In an attempt to replicate the findings from the Scandinavian sample, the association between rs1801133 and age at onset was also analyzed in Chinese high-risk families, with two or more affected siblings (n = 243). Among the Scandinavian patients the functional MTHFR SNP rs1801133 (C677T) significantly affected age at onset of schizophrenia in a dose-dependent manner (P = 0.0015), with lower age of onset with increasing numbers of the mutant T-allele. There was no evidence of rs1801131 (A1298C) affecting age of onset in schizophrenia. Within the Chinese high-risk families carriers of the MTHFR 677T allele showed earlier age at onset than siblings being homozygous for the wild-type allele (P = 0.008). The MTHFR C677T polymorphism may play a role as a modifying factor for age of onset in schizophrenia.
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| 8. |
- Alnaes, Dag, et al.
(författare)
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Brain Heterogeneity in Schizophrenia and Its Association With Polygenic Risk
- 2019
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Ingår i: JAMA psychiatry. - : AMER MEDICAL ASSOC. - 2168-6238 .- 2168-622X. ; 76:7, s. 739-748
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Tidskriftsartikel (refereegranskat)abstract
- ImportanceBetween-individual variability in brain structure is determined by gene-environment interactions, possibly reflecting differential sensitivity to environmental and genetic perturbations. Magnetic resonance imaging (MRI) studies have revealed thinner cortices and smaller subcortical volumes in patients with schizophrenia. However, group-level comparisons may mask considerable within-group heterogeneity, which has largely remained unnoticed in the literature. ObjectivesTo compare brain structural variability between individuals with schizophrenia and healthy controls and to test whether respective variability reflects the polygenic risk score (PRS) for schizophrenia in an independent sample of healthy controls. Design, Setting, and ParticipantsThis case-control and polygenic risk analysis compared MRI-derived cortical thickness and subcortical volumes between healthy controls and patients with schizophrenia across 16 cohorts and tested for associations between PRS and MRI features in a control cohort from the UK Biobank. Data were collected from October 27, 2004, through April 12, 2018, and analyzed from December 3, 2017, through August 1, 2018. Main Outcomes and MeasuresMean and dispersion parameters were estimated using double generalized linear models. Vertex-wise analysis was used to assess cortical thickness, and regions-of-interest analyses were used to assess total cortical volume, total surface area, and white matter, subcortical, and hippocampal subfield volumes. Follow-up analyses included within-sample analysis, test of robustness of the PRS threshold, population covariates, outlier removal, and control for image quality. ResultsA comparison of 1151 patients with schizophrenia (mean [SD] age,33.8[10.6] years; 68.6% male [n=790] and 31.4% female [n=361]) with 2010 healthy controls (mean [SD] age,32.6[10.4] years; 56.0% male [n=1126] and 44.0% female [n=884]) revealed higher heterogeneity in schizophrenia for cortical thickness and area (t = 3.34), cortical (t=3.24) and ventricle (t range, 3.15-5.78) volumes, and hippocampal subfields (t range, 2.32-3.55). In the UK Biobank sample of 12 490 participants (mean [SD] age,55.9 [7.5] years; 48.2% male [n=6025] and 51.8% female [n=6465]), higher PRS was associated with thinner frontal and temporal cortices and smaller left CA2/3 (t=-3.00) but was not significantly associated with dispersion. Conclusions and RelevanceThis study suggests that schizophrenia is associated with substantial brain structural heterogeneity beyond the mean differences. These findings may reflect higher sensitivity to environmental and genetic perturbations in patients, supporting the heterogeneous nature of schizophrenia. A higher PRS was associated with thinner frontotemporal cortices and smaller hippocampal subfield volume, but not heterogeneity. This finding suggests that brain variability in schizophrenia results from interactions between environmental and genetic factors that are not captured by the PRS. Factors contributing to heterogeneity in frontotemporal cortices and hippocampus are key to furthering our understanding of how genetic and environmental factors shape brain biology in schizophrenia.
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| 9. |
- Andreou, Dimitrios, et al.
(författare)
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Associations between a locus downstream DRD1 gene and cerebrospinal fluid dopamine metabolite concentrations in psychosis
- 2016
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 619, s. 126-130
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Tidskriftsartikel (refereegranskat)abstract
- Dopamine activity, mediated by the catecholaminergic neurotransmitter dopamine, is prominent in the human brain and has been implicated in schizophrenia. Dopamine targets five different receptors and is then degraded to its major metabolite homovanillic acid (HVA). We hypothesized that genes encoding dopamine receptors may be associated with cerebrospinal fluid (CSF) HVA concentrations in patients with psychotic disorder. We searched for association between 67 single nucleotide polymorphisms (SNPs) in the five dopamine receptor genes i.e., DRD1, DRD2, DRD3, DRD4 and DRD5, and the CSF HVA concentrations in 74 patients with psychotic disorder. Nominally associated SNPs were also tested in 111 healthy controls. We identified a locus, located downstream DRD1 gene, where four SNPs, rs11747728, rs11742274, rs265974 and rs11747886, showed association with CSF HVA concentrations in psychotic patients. The associations between rs11747728, which is a regulatory region variant, and rs11742274 with HVA remained significant after correction for multiple testing. These associations were restricted to psychotic patients and were absent in healthy controls. The results suggest that the DRD1 gene is implicated in the pathophysiology of psychosis and support the dopamine hypothesis of schizophrenia.
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| 10. |
- Andreou, Dimitrios, et al.
(författare)
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Cardiac left ventricular ejection fraction in men and women with schizophrenia on long-term antipsychotic treatment
- 2020
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Ingår i: Schizophrenia Research. - : Elsevier BV. - 0920-9964 .- 1573-2509. ; 218, s. 226-232
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Tidskriftsartikel (refereegranskat)abstract
- Patients with schizophrenia exhibit a higher cardiovascular mortality compared to the general population which has been attributed to life-style factors, genetic susceptibility and antipsychotic medication. Recent echocardiographic studies have pointed to an association between clozapine treatment and reduced left ventricular ejection fraction (LVEF), a measure that has been inversely associated with adverse outcomes including all-cause mortality. Cardiovascular magnetic resonance (CMR) is considered the reference method for LVEF measurement. The aim of the present study was to investigate the LVEF in patients with schizophrenia on long-term treatment with antipsychotics and healthy controls. Twenty-nine adult patients with schizophrenia on long-term medication with antipsychotics and 27 age-, sex- and body mass index-matched healthy controls (mean ages 44 and 45 years, respectively) were recruited from outpatient psychiatric clinics in Uppsala, Sweden. The participants were interviewed and underwent physical examination, biochemical analyses, electrocardiogram and CMR. Men with schizophrenia on long-term antipsychotic treatment showed significantly lower LVEF than controls (p = 0.0076), whereas no such difference was evident among women (p = 0.44). Specifically, clozapine-treated male patients had 10.6% lower LVEF than male controls (p = 0.0064), whereas the LVEF was 5.5% below that of controls among male patients treated with non-clozapine antipsychotics (p = 0.047). Among medicated men with schizophrenia, we found significantly lower LVEF compared to healthy individuals, suggesting the need of routine cardiac monitoring in this patient group. This is the first study showing a significant negative association between treatment with non-clozapine antipsychotics and LVEF.
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