| 1. |
- Chang, Hong, et al.
(författare)
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Identification of a Bipolar Disorder Vulnerable Gene CHDH at 3p21.1.
- 2017
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Ingår i: Molecular neurobiology. - : Springer Science and Business Media LLC. - 1559-1182 .- 0893-7648. ; 54:7, s. 5166-5176
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide analysis (GWA) is an effective strategy to discover extreme effects surpassing genome-wide significant levels in studying complex disorders; however, when sample size is limited, the true effects may fail to achieve genome-wide significance. In such case, there may be authentic results among the pools of nominal candidates, and an alternative approach is to consider nominal candidates but are replicable across different samples. Here, we found that mRNA expression of the choline dehydrogenase gene (CHDH) was uniformly upregulated in the brains of bipolar disorder (BPD) patients compared with healthy controls across different studies. Follow-up genetic analyses of CHDH variants in multiple independent clinical datasets (including 11,564 cases and 17,686 controls) identified a risk SNP rs9836592 showing consistent associations with BPD (P meta=5.72×10(-4)), and the risk allele indicated an increased CHDH expression in multiple neuronal tissues (lowest P=6.70×10(-16)). These converging results may identify a nominal but true BPD susceptibility gene CHDH. Further exploratory analysis revealed suggestive associations of rs9836592 with childhood intelligence (P=0.044) and educational attainment (P=0.0039), a "proxy phenotype" of general cognitive abilities. Intriguingly, the CHDH gene is located at chromosome 3p21.1, a risk region implicated in previous BPD genome-wide association studies (GWAS), but CHDH is lying outside of the core GWAS linkage disequilibrium (LD) region, and our studied SNP rs9836592 is ∼1.2Mb 3' downstream of the previous GWAS loci (e.g., rs2251219) with no LD between them; thus, the association observed here is unlikely a reflection of previous GWAS signals. In summary, our results imply that CHDH may play a previously unknown role in the etiology of BPD and also highlight the informative value of integrating gene expression and genetic code in advancing our understanding of its biological basis.
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| 2. |
- Charney, Alexander W, et al.
(författare)
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Contribution of Rare Copy Number Variants toBipolar Disorder Risk Is Limited to Schizoaffective Cases.
- 2019
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Ingår i: Biological psychiatry. - : Elsevier BV. - 1873-2402 .- 0006-3223. ; 86:2, s. 110-119
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Tidskriftsartikel (refereegranskat)abstract
- Genetic risk for bipolar disorder (BD) is conferred through many common alleles, while a role for rare copy number variants (CNVs) is less clear. Subtypes of BD including schizoaffective disorder bipolar type (SAB), bipolar I disorder (BD I), and bipolar II disorder (BD II) differ according to the prominence and timing of psychosis, mania, and depression. The genetic factors contributing to the combination of symptoms among these subtypes are poorly understood.Rare large CNVs were analyzed in 6353 BD cases (3833 BD I [2676 with psychosis, 850 without psychosis, and 307 with unknown psychosis history], 1436 BD II, 579 SAB, and 505 BD not otherwise specified) and 8656 controls. CNV burden and a polygenic risk score (PRS) for schizophrenia were used to evaluate the relative contributions of rare and common variants to risk of BD, BD subtypes, and psychosis.CNV burden did not differ between BD and controls when treated as a single diagnostic entity. However, burden in SAB was increased relative to controls (p= .001), BD I (p= .0003), and BD II (p= .0007). Burden and schizophrenia PRSs were increased in SAB compared with BD I with psychosis (CNV p= .0007, PRS p= .004), and BD I without psychosis (CNV p= .0004, PRS p= 3.9× 10-5). Within BD I, psychosis was associated with increased schizophrenia PRSs (p= .005) but not CNV burden.CNV burden in BD is limited to SAB. Rare and common genetic variants may contribute differently to risk for psychosis and perhaps other classes of psychiatric symptoms.
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| 3. |
- Hou, Liping, et al.
(författare)
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Genome-wide association study of 40,000 individuals identifies two novel loci associated with bipolar disorder.
- 2016
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 25:15, s. 3383-94
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) is a genetically complex mental illness characterized by severe oscillations of mood and behavior. Genome-wide association studies (GWAS) have identified several risk loci that together account for a small portion of the heritability. To identify additional risk loci, we performed a two-stage meta-analysis of >9 million genetic variants in 9,784 bipolar disorder patients and 30,471 controls, the largest GWAS of BD to date. In this study, to increase power we used ∼2,000 lithium-treated cases with a long-term diagnosis of BD from the Consortium on Lithium Genetics, excess controls, and analytic methods optimized for markers on the X-chromosome. In addition to four known loci, results revealed genome-wide significant associations at two novel loci: an intergenic region on 9p21.3 (rs12553324, p=5.87×10(-9); odds ratio=1.12) and markers within ERBB2 (rs2517959, p=4.53×10(-9); odds ratio=1.13). No significant X-chromosome associations were detected and X-linked markers explained very little BD heritability. The results add to a growing list of common autosomal variants involved in BD and illustrate the power of comparing well-characterized cases to an excess of controls in GWAS.
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| 4. |
- Hughes, Timothy, et al.
(författare)
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A Loss-of-Function Variant in a Minor Isoform of ANK3 Protects Against Bipolar Disorder and Schizophrenia.
- 2016
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Ingår i: Biological psychiatry. - : Elsevier BV. - 1873-2402 .- 0006-3223. ; 80:4, s. 323-330
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Tidskriftsartikel (refereegranskat)abstract
- Ankyrin-3 (ANK3) was one of the first genes to reach significance in a bipolar disorder genome-wide association study. Many subsequent association studies confirmed this finding and implicated this gene in schizophrenia. However, the exact nature of the role of ANK3 in the pathophysiology remains elusive. In particular, the specific isoforms involved and the nature of the imbalance are unknown.
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| 5. |
- Martin, Cederlöf, 1980-, et al.
(författare)
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Acute intermittent porphyria : comorbidity and shared familial risks with schizophrenia and bipolar disorder in Sweden
- 2015
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Ingår i: British Journal of Psychiatry. - London, United Kingdom : Royal College of Psychiatrists. - 0007-1250 .- 1472-1465. ; 207:6, s. 556-557
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Tidskriftsartikel (refereegranskat)abstract
- Acute intermittent porphyria (AIP) has been associated with schizophrenia in some studies, but prior research is limited by the absence of comparison populations. Here, we linked Swedish registers to examine the risk of schizophrenia and bipolar disorder in 717 individuals diagnosed with AIP and their first-degree relatives, compared with matched individuals without AIP and their first-degree relatives. Individuals with AIP had a fourfold increased risk of schizophrenia or bipolar disorder. Similarly, relatives of individuals with AIP had double the risk of schizophrenia or bipolar disorder, suggesting that these associations may be as a result of common genetic influences.
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| 6. |
- Martin, Cederlöf, 1980-, et al.
(författare)
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The association between Darier disease, bipolar disorder, and schizophrenia revisited: a population-based family study.
- 2015
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Ingår i: Bipolar disorders. - Hoboken, USA : Wiley. - 1399-5618 .- 1398-5647. ; 17:3, s. 340-4
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Tidskriftsartikel (refereegranskat)abstract
- Darier disease is an autosomal dominant skin disorder caused by mutations in the ATPase, Ca++ transporting, cardiac muscle, slow twitch 2 (ATP2A2) gene and previously reported to cosegregate with bipolar disorder and schizophrenia in occasional pedigrees. It is, however, unknown whether these associations exist also in the general population, and the objective of this study was to examine this question.
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| 7. |
- Smedler, Erik, et al.
(författare)
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Genes, biomarkers, and clinical features associated with the course of bipolar disorder.
- 2019
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Ingår i: European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. - : Elsevier BV. - 1873-7862. ; 29:10, s. 1152-1160
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Tidskriftsartikel (refereegranskat)abstract
- There is considerable variability in the severity of bipolar disorder, e.g., in terms of the frequency of inpatient episodes. The long-term progression also differs, where some patients are sensitised with progressively shorter healthy intervals. Little is known about the proportion of patients being sensitised, their clinical characteristics, and biological underpinnings. We analysed long-term progression of bipolar disorder in relation to clinical characteristics (N=3074), serum biomarkers (N=745), and genetic variants (N=1401) in a cohort of Swedish bipolar disorder patients. We took advantage of the National Patient Register, providing reliable data on 35,973 psychiatric inpatient care episodes in Sweden since 1973. First, one third of the cohort cluster together with a maximum of one inpatient episode per year, while the remaining two thirds had >1 episode per year. These groups did not differ with respect to clinical features or biomarkers. Second, among patients with at least five inpatient episodes (defined as severely ill), we find one group with progressively shorter cycle-lengths (one fifth of the total cohort, N=550). Compared with those with a stable or recuperant trajectory, these patients featured lower functioning, more antidepressant treatment, as well as reduced levels of inflammatory markers in serum. Third, sensitisation was associated with a common genetic variant near the calcium channel gene CACNA2D3 at genome-wide significance. These results suggest the potential for translational research aimed at preventive actions.
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| 8. |
- Song, Jie, et al.
(författare)
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Bipolar disorder and its relation to major psychiatric disorders : a family-based study in the Swedish population
- 2015
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Ingår i: Bipolar Disorders. - Stockholm : Wiley-Blackwell. - 1398-5647 .- 1399-5618. ; 17:2, s. 184-193
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Bipolar disorder (BPD) shares genetic components with other psychiatric disorders; however, uncertainty remains about where in the psychiatric spectra BPD falls. To understand the etiology of BPD, we studied the familial aggregation of BPD and co-aggregation between BPD and schizophrenia, depression, anxiety disorders, attention-deficit hyperactivity disorder, drug abuse, personality disorders, and autism spectrum disorders.METHODS: A population-based cohort was created by linking several Swedish national registers. A total of 54,723 individuals with BPD were identified among 8,141,033 offspring from 4,149,748 nuclear families. The relative risk of BPD in relatives and the co-occurrence of other psychiatric disorders in patients with BPD and their relatives were compared to those of matched-population controls. Structural equation modeling was used to estimate the heritability and tetrachoric correlation.RESULTS: The familial risks for relatives of BPD probands were 5.8-7.9 in first-degree relatives, and decreased with genetic distance. Co-occurrence risks for other psychiatric disorders were 9.7-22.9 in individuals with BPD and 1.7-2.8 in full siblings of BPD probands. Heritability for BPD was estimated at 58%. The correlations between BPD and other psychiatric disorders were considerable (0.37-0.62) and primarily due to genetic effects. The correlation with depression was the highest (0.62), and was 0.44 for schizophrenia.CONCLUSIONS: The high familial risks provide evidence that genetic factors play an important role in the etiology of BPD, and the shared genetic determinants suggest pleiotropic effects across different psychiatric disorders. Results also indicate that BPD is in both the mood and psychotic spectra, but possibly more closely related to mood disorders.
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| 9. |
- Song, Jie, et al.
(författare)
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Specificity in Etiology of Subtypes of Bipolar Disorder : Evidence From a Swedish Population-Based Family Study
- 2018
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Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 84:11, s. 810-816
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Tidskriftsartikel (refereegranskat)abstract
- Background: Uncertainty remains whether bipolar I disorder (BDI) and bipolar II disorder (BDII) differ etiologically. We used a population-based family sample to examine the etiological boundaries between BDI and BDII by assessing their familial aggregation/coaggregation and by assessing the coaggregation between them and schizophrenia, depression, attention-deficit/hyperactivity disorder, eating disorders, autism spectrum disorder, substance use disorders, anxiety disorders, and personality disorders.Methods: By linking Swedish national registers, we established a population-based cohort (N = 15,685,511) and identified relatives with different biological relationships. Odds ratios (ORs) were used to measure the relative risk of BDI and BDII in relatives of individuals diagnosed with BDI (n = 4309) and BDII (n = 4178). The heritability for BDI and BDII and the genetic correlation across psychiatric disorders were estimated by variance decomposition analysis.Results: Compared with the general population, the OR of BDI was 17.0 (95% confidence interval [CI] 13.1-22.0) in first-degree relatives of BDI patients, higher than that of BDII patients (OR 9.8, 95% CI 7.7-12.5). The ORs of BDII were 13.6 (95% CI 10.2-18.2) in first-degree relatives of BDII patients and 9.8 (95% CI 7.7-12.4) in relatives of BDI patients. The heritabilities for BDI and BDII were estimated at 57% (95% CI 32%-79%) and 46% (95% CI 21%-67%), respectively, with a genetic correlation estimated as 0.78 (95% CI 0.36-1.00). The familial coaggregation of other psychiatric disorders, in particular schizophrenia, showed different patterns for BDI and BDII.Conclusions: Our results suggest a distinction between BDI and BDII in etiology, partly due to genetic differences.
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| 10. |
- Song, Jie, et al.
(författare)
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Suicidal Behavior During Lithium and Valproate Treatment : A Within-Individual 8-Year Prospective Study of 50,000 Patients With Bipolar Disorder
- 2017
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Ingår i: American Journal of Psychiatry. - : American Psychiatric Association. - 0002-953X .- 1535-7228. ; 174:8, s. 795-802
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Conclusions regarding lithium's antisuicidal effect for bipolar disorder have been limited due to nonrepresentative subjects and potential confounding factors, including varying severity of illness. Findings regarding the effect of valproate, the most common alternative to lithium, are inconsistent for suicidal behavior. This study investigated the associations of these two drugs with the risk of suicide-related events, and possible differences between drugs, by using within-individual designs in a register-based longitudinal cohort.Method: Through linkage of multiple Swedish national registers, 51,535 individuals with bipolar disorder were followed from 2005 to 2013 for treatment with lithium and valproate. Stratified Cox regression was used to estimate the hazard ratios of suicide-related events during treated periods compared with untreated periods. For significant associations between medication and suicide-related events, the population attributable fraction was estimated to assess the public health impact for patients with bipolar disorder.Results: During follow-up, 10,648 suicide-related events occurred. The incidence rate was significantly decreased by 14% during lithium treatment (hazard ratio 0.86, 95% confidence interval [CI] 0.78-0.95) but not during valproate treatment (hazard ratio 1.02, 95% CI 0.89-1.15). The difference in hazard ratios of suicide-related events between lithium and valproate was statistically significant. Estimates of the population attributable fraction suggested that 12% (95% CI 4% 220%) of suicide-related events could have been avoided if patients had taken lithium during the entire follow-up.Conclusions: The results suggest that lithium should be considered for patients with bipolar disorder with suspected suicidal intentions, although risk for suicide is only one of the considerations when providing clinical care.
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