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| 2. |
- Ceulemans, Shana, et al.
(författare)
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Evidence for the involvement of the glucocorticoid receptor gene in bipolar disorder in an isolated northern Swedish population
- 2011
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Ingår i: Bipolar Disorders. - Malden, USA : John Wiley & Sons. - 1398-5647 .- 1399-5618. ; 13:7-8, s. 614-623
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis is one of the most consistent findings in the pathophysiology of mood disorders. The potential role of genes related to HPA axis function has been investigated extensively in major depression. However, in bipolar disorder (BPD) such studies are scarce. We performed a systematic HapMap-based association study of six genes crucial for HPA axis function in relation to BPD. Methods: Haplotype tagging single nucleotide polymorphisms (htSNPs) were selected in order to identify all haplotypes with a frequency of more than 1% in the genes encoding the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), corticotrophin releasing hormone receptor 1 (CRH-R1) and 2 (CRH-R2), CRH binding protein (CRH-BP), and FK binding protein 5 (FKBP5). This resulted in a total selection of 225 SNPs that were genotyped and analyzed in 309 BPD patients and 364 matched control individuals all originating from an isolated northern Swedish population. Results: Consistent evidence for an association with BPD was found for NR3C1, the gene encoding GR. Almost all SNPs in two adjacent haplotype blocks contributed to the positive signal, comprised of significant single marker, sliding window, and haplotype-specific p-values. All these results point to a moderately frequent (10–15%) susceptibility haplotype covering the entire coding region and 3? untranslated region (UTR) of NR3C1. Conclusions: This study contributes to the growing evidence for a role of the glucocorticoid receptor gene (NR3C1) in vulnerability to mood disorders, and BPD in particular, and warrants further in vitro investigation of the at-risk haplotypes with respect to disease etiology. However, this association might be restricted to this specific population, as it is observed in a rather small sample from an isolated population without replication, and data from large meta-analyses for genome-wide association studies in BPD do not show the GR as a very strong candidate.
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| 3. |
- Moens, Lotte N, et al.
(författare)
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Sequencing of DISC1 Pathway Genes Reveals Increased Burden of Rare Missense Variants in Schizophrenia Patients from a Northern Swedish Population
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:8, s. e23450-
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, DISC1 has emerged as one of the most credible and best supported candidate genes for schizophrenia and related neuropsychiatric disorders. Furthermore, increasing evidence - both genetic and functional - indicates that many of its protein interaction partners are also involved in the development of these diseases. In this study, we applied a pooled sample 454 sequencing strategy, to explore the contribution of genetic variation in DISC1 and 10 of its interaction partners (ATF5, Grb2, FEZ1, LIS-1, PDE4B, NDE1, NDEL1, TRAF3IP1, YWHAE, and ZNF365) to schizophrenia susceptibility in an isolated northern Swedish population. Mutation burden analysis of the identified variants in a population of 486 SZ patients and 514 control individuals, revealed that non-synonymous rare variants with a MAF<0.01 were significantly more present in patients compared to controls (8.64% versus 4.7%, P = 0.018), providing further evidence for the involvement of DISC1 and some of its interaction partners in psychiatric disorders. This increased burden of rare missense variants was even more striking in a subgroup of early onset patients (12.9% versus 4.7%, P = 0.0004), highlighting the importance of studying subgroups of patients and identifying endophenotypes. Upon investigation of the potential functional effects associated with the identified missense variants, we found that similar to 90% of these variants reside in intrinsically disordered protein regions. The observed increase in mutation burden in patients provides further support for the role of the DISC1 pathway in schizophrenia. Furthermore, this study presents the first evidence supporting the involvement of mutations within intrinsically disordered protein regions in the pathogenesis of psychiatric disorders. As many important biological functions depend directly on the disordered state, alteration of this disorder in key pathways may represent an intriguing new disease mechanism for schizophrenia and related neuropsychiatric diseases. Further research into this unexplored domain will be required to elucidate the role of the identified variants in schizophrenia etiology.
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| 4. |
- Mousavi, Malahat, et al.
(författare)
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Serum metabolomic biomarkers of dementia
- 2014
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Ingår i: Dementia and Geriatric Cognitive Disorders Extra. - : S. Karger AG. - 1664-5464. ; 4:2, s. 252-62
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Tidskriftsartikel (refereegranskat)abstract
- Aims: This study compared serum metabolites of demented patients (Alzheimer's disease and vascular dementia) and controls, and explored serum metabolite profiles of nondemented individuals 5 years preceding the diagnosis. Methods: Cognitively healthy participants were followed up for 5-20 years. Cognitive assessment, serum sampling, and diagnosis were completed every 5 years. Multivariate analyses were conducted on the metabolite profiles generated by gas chromatography/time-of-flight mass spectrometry. Results: A significant group separation was found between demented patients and controls, and between incident cases and controls. Metabolites that contributed in both analyses were 3,4-dihydroxybutanoic acid, docosapentaenoic acid, and uric acid. Conclusions: Serum metabolite profiles are altered in demented patients, and detectable up to 5 years preceding the diagnosis. Blood sampling can make an important contribution to the early prediction of conversion to dementia.
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| 6. |
- Sköld, Mia, et al.
(författare)
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Thalamocortical abnormalities in auditory brainstem response patterns distinguish DSM-IV bipolar disorder type I from schizophrenia
- 2014
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327 .- 1573-2517. ; 169, s. 105-11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Bipolar disorder type I (BP-I) belongs to a spectrum of affective disorders that are expressed in many different ways and therefore can be difficult to distinguish from other conditions, especially unipolar depression, schizoaffective disorder, schizophrenia (SZ), but also anxiety and personality disorders. Since early diagnosis and treatment have shown to improve the long-term prognosis, complementary specific biomarkers are of great value. The auditory brainstem response (ABR) has previously been applied successfully to identify specific abnormal ABR patterns in SZ and Asperger syndrome.METHODS: The current study investigated the early auditory processing of complex sound stimuli e.g. forward masking, in BP-I compared to SZ patients. The ABR curves of BP-I patients (n=23) and SZ patients (n=20) were analyzed in terms of peak amplitudes and correlation with an ABR norm curve based on a non-psychiatric control group (n=20).RESULTS: BP-I patients had significantly higher wave III (p=0.0062) and wave VII (p=0.0472) amplitudes compared with SZ patients. Furthermore, BP-I patients, and to a lesser extent SZ patients, showed low correlation with the norm ABR curve in the part of the curve comprising waves VI-VII.LIMITATIONS: Sample size was relatively small and study groups were not matched for age and gender.CONCLUSIONS: BP-I patients showed specific aberrances, specifically in the latter part of the ABR curve, implicating abnormalities in thalamocortical circuitry. The abnormal ABR wave patterns significantly separated BP-I patients from SZ patients suggesting that ABR might serve as a biomarker for BP-I.
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| 7. |
- Van Den Bossche, Maarten J., et al.
(författare)
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Identification of a CACNA2D4 deletion in late onset bipolar disorder patients and implications for the involvement of voltage-dependent calcium channels in psychiatric disorders
- 2012
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Ingår i: American Journal of Medical Genetics Part B. - : Wiley. - 1552-4841 .- 1552-485X. ; 159B:4, s. 465-475
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Tidskriftsartikel (refereegranskat)abstract
- The GWAS-based association of CACNA1C with bipolar disorder (BPD) is one of the strongest genetic findings to date. CACNA1C belongs to the family of CACN genes encoding voltage-dependent calcium channels (VDCCs). VDCCs are involved in brain circuits and cognitive processes implicated in BPD and schizophrenia (SZ). Recently, it was shown that rare copy number variations (CNVs) are found at an increased frequency in SZ and to a lesser extent also in BPD, suggesting the involvement of CNVs in the causation of these diseases. We hypothesize that CNVs in CACN genes can influence the susceptibility to BPD, SZ, and/or schizoaffective disorder (SZA). A search for CNVs in eight CACN genes in a patient-control sample of European decent was performed. A total of 709 BP patients, 645 SZ patients, 189 SZA patients, and 1,470 control individuals were screened using the Multiplex Amplicon Quantification (MAQ) method. We found a rare, partial deletion of 35.7?kb in CACNA2D4 in two unrelated late onset bipolar I patients and in one control individual. All three deletions shared the same breakpoints removing exons 1726 of CACNA2D4, comprising part of the CACHE domain. Based on the data we cannot claim causality to BPD of the identified CACNA2D4 deletion but nevertheless this deletion can be important in unraveling the underlying processes leading to psychiatric diseases in general and BPD in particular.
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| 8. |
- Van Den Bossche, Maarten J., et al.
(författare)
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Rare copy number variants in neuropsychiatric disorders : Specific phenotype or not?
- 2012
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Ingår i: American Journal of Medical Genetics Part B. - : Wiley. - 1552-4841 .- 1552-485X. ; 159B:7, s. 812-822
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Tidskriftsartikel (refereegranskat)abstract
- From a number of genome-wide association studies it was shown that de novo and/or rare copy number variants (CNVs) are found at an increased frequency in neuropsychiatric diseases. In this study we examined the prevalence of CNVs in six genomic regions (1q21.1, 2p16.3, 3q29, 15q11.2, 15q13.3, and 16p11.2) previously implicated in neuropsychiatric diseases. Hereto, a cohort of four neuropsychiatric disorders (schizophrenia, bipolar disorder, major depressive disorder, and intellectual disability) and control individuals from three different populations was used in combination with Multilpex Amplicon Quantifiaction (MAQ) assays, capable of high resolution (kb range) and custom-tailored CNV detection. Our results confirm the etiological candidacy of the six selected CNV regions for neuropsychiatric diseases. It is possible that CNVs in these regions can result in disturbed brain development and in this way lead to an increased susceptibility for different neuropsychiatric disorders, dependent on additional genetic and environmental factors. Our results also suggest that the neurodevelopmental component is larger in the etiology of schizophrenia and intellectual disability than in mood disorders. Finally, our data suggest that deletions are in general more pathogenic than duplications. Given the high frequency of the examined CNVs (12%) in patients of different neuropsychiatric disorders, screening of large cohorts with an affordable and feasible method like the MAQ assays used in this study is likely to result in important progress in unraveling the genetic factors leading to an increased susceptibility for several psychiatric disorders.
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| 9. |
- Wikgren, Mikael, 1981-, et al.
(författare)
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Shorter telomere length is linked to brain atrophy and white matter hyperintensities
- 2014
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Ingår i: Age and Ageing. - : Oxford University Press (OUP). - 0002-0729 .- 1468-2834. ; 43:2, s. 212-217
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Tidskriftsartikel (refereegranskat)abstract
- Background: leukocyte telomere length (TL) is considered a marker of biological aging. Several studies have investigated the link between leukocyte TL and aging-associated functional attributes of the brain, but no prior study has investigated whether TL can be linked to brain atrophy and white matter hyperintensities (WMHs); two prominent structural manifestations of brain aging. Methods: we investigated whether leukocyte TL was related to brain atrophy and WMHs in a sample of 102 non-demented individuals aged 64-75 years. Results: shorter TL was related to greater degree of subcortical atrophy (beta = -0.217, P = 0.034), but not to cortical atrophy. Furthermore, TL was 371 bp shorter (P = 0.041) in participants exhibiting subcortical WMHs, and 552 bp shorter (P = 0.009) in older participants exhibiting periventricular WMHs. Conclusion: this study provides the first evidence of leukocyte TL being associated with cerebral subcortical atrophy and WMHs, lending further support to the concept of TL as a marker of biological aging, and in particular that of the aging brain.
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