Age dependent association of inbreeding with risk for schizophrenia in Egypt.
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ABSTRACT: Background
Self-reported consanguinity is associated with risk for schizophrenia (SZ) in several inbred populations, but estimates using DNA-based coefficients of inbreeding are unavailable. Further, it is not known whether recessively inherited risk mutations can be identified through homozygosity by descent (HBD) mapping.Methods
We studied self-reported and DNA-based estimates of inbreeding among Egyptian patients with SZ (n = 421, DSM IV criteria) and adult controls without psychosis (n = 301), who were evaluated using semi-structured diagnostic interview schedules and genotyped using the Illumina Infinium PsychArray. Following quality control checks, coefficients of inbreeding (F) and regions of homozygosity (ROH) were estimated using PLINK software for HBD analysis. Exome sequencing was conducted in selected cases.Results
Inbreeding was associated with schizophrenia based on self-reported consanguinity (χ2 = 4.506, 1 df, p = 0.034) and DNA-based estimates for inbreeding (F); the latter with a significant F × age interaction (β = 32.34, p = 0.0047). The association was most notable among patients older than age 40 years. Eleven ROH were over-represented in cases on chromosomes 1, 3, 6, 11, and 14; all but one region is novel for schizophrenia risk. Exome sequencing identified six recessively-acting genes in ROH with loss-of-function variants; one of which causes primary hereditary microcephaly.Conclusions
We propose consanguinity as an age-dependent risk factor for SZ in Egypt. HBD mapping is feasible for SZ in adequately powered samples.
SUBMITTER: McClain L
PROVIDER: S-EPMC8054776 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:Consanguinity has been suggested as a risk factor for psychoses in some Middle Eastern countries, but adequate control data are unavailable. Our recent studies in Egypt have shown elevated parental consanguinity rates among patients with bipolar I disorder (BP1), compared with controls. We have now extended our analyses to schizophrenia (SZ) in the same population. METHODS:A case-control study was conducted at Mansoura University Hospital, Mansoura, Egypt (SZ, n=75; controls, n=126, and their available parents). The prevalence of consanguinity was estimated from family history data ('self report'), followed by DNA analysis using short tandem repeat polymorphisms (STRPs, n=63) ('DNA-based' rates). RESULTS:Self-reported consanguinity was significantly elevated among the patients (SZ: 46.6%, controls: 19.8%, OR 3.53, 95% CI 1.88, 6.64; p=0.000058, 1 d.f.). These differences were confirmed using DNA-based estimates for coefficients of inbreeding (inbreeding coefficients as means+/-standard error, cases: 0.058+/-0.007, controls: 0.022+/-0.003). CONCLUSIONS:Consanguinity rates are significantly elevated among Egyptian SZ patients in the Nile delta region. The associations are similar to those observed with BP1 in our earlier study. If replicated, the substantial risk associated with consanguinity raises public health concerns. They may also pave the way for gene mapping studies.
| S-EPMC2900407 | biostudies-literature
Project description:Schizotypal personality traits may increase proneness to psychosis and likely index familial vulnerability to schizophrenia (SZ), implying shared genetic determinants with SZ. Here, we sought to investigate the contribution of common genetic risk variation for SZ on self-reported schizotypy in 2 ethnically homogeneous cohorts of healthy young males during compulsory military service, enrolled in the Athens Study of Proneness and Incidence of Schizophrenia (ASPIS, N = 875) and the Learning on Genetics of Schizophrenia Spectrum study (LOGOS, N = 690). A follow-up psychometric assessment was performed in a sub-sample of the ASPIS (N = 121), 18 months later at military service completion. Polygenic risk scores (PRS) for SZ were derived based on genome-wide association meta-analysis results from the Psychiatric Genomics Consortium. In the ASPIS, higher PRSSZ significantly associated with lower levels of positive (ie, perceptual distortions), disorganization and paranoid facets of schizotypy, whereas no association with negative (ie, interpersonal) facets was noted. Importantly, longitudinal data analysis in the ASPIS subsample revealed that PRSSZ was inversely associated with positive schizotypy at military induction (stressed condition) but not at follow-up (nonstressed condition), providing evidence for environmental rather than SZ-implicated genetic influences. Moreover, consistent with prior reports, PRSSZ was positively correlated with trait anxiety in the LOGOS and additionally the recruits with higher PRSSZ and trait anxiety exhibited attenuated paranoid ideation. Together, these findings do not support an etiological link between increased polygenic liability for SZ and schizotypy, suggesting that psychosocial stress or trait anxiety may impact schizotypal phenotypic expressions among healthy young adults not genetically predisposed to SZ.
| S-EPMC5814832 | biostudies-other
Project description:Background There have been limited data examining the age-dependent relationship of wide-range risk factors with the incidence of each subtype of cardiovascular disease (CVD) event. We assessed age-related associations between modifiable risk factors and the incidence of CVD. Methods and Results We analyzed 3 027 839 participants without a CVD history enrolled in the JMDC Claims Database (mean age, 44.8±11.0 years; 57.6% men). Each participant was categorized as aged 20 to 49 years (n=2 008 559), 50 to 59 years (n=712 273), and 60 to 75 years (n=307 007). Using Cox proportional hazards models and the relative risk reduction, we identified associations between risk factors and incident CVD, consisting of myocardial infarction, angina pectoris, stroke, and heart failure (HF). We assessed whether the association of risk factors for developing CVD would be modified by age category. Over a mean follow-up of 1133 days, 6315 myocardial infarction, 56 447 angina pectoris, 28 079 stroke, and 56 369 HF events were recorded. The incidence of myocardial infarction, angina pectoris, stroke, and HF increased with age category. Hazard ratios of obesity, hypertension, and diabetes in the multivariable Cox regression analyses for myocardial infarction, angina pectoris, stroke, and HF decreased with age category. The relative risk reduction of obesity, hypertension, and diabetes for CVD events decreased with age category. For example, the relative risk reduction of hypertension for HF decreased from 59.2% in participants aged 20 to 49 years to 38.1% in those aged 60 to 75 years. Conclusions The contribution of modifiable risk factor to the development of CVD is greater in younger compared with older individuals. Preventive efforts for risk factor modification may be more effective in younger people.
| S-EPMC9939069 | biostudies-literature
Project description:We resolved the convergent impact of ten eGenes with strong evidence of up-regulation by Psychiatric Genomics Consortium (PGC3)-SCZ GWAS loci: CALN1, CLCN3, FES, NAGA, PLCL1, SF3B1, TMEM219, UBE2Q2L, ZNF823, ZNF804A.
2023-02-01 | GSE200774 | GEO
Project description:ImportanceUrban life has been proposed as an environmental risk factor accounting for the increased prevalence of schizophrenia in urban areas. An alternative hypothesis is that individuals with increased genetic risk tend to live in urban/dense areas.ObjectiveTo assess whether adults with higher genetic risk for schizophrenia have an increased probability to live in more populated areas than those with lower risk.Design, setting, and participantsFour large, cross-sectional samples of genotyped individuals of European ancestry older than 18 years with known addresses in Australia, the United Kingdom, and the Netherlands were included in the analysis. Data were based on the postcode of residence at the time of last contact with the participants. Community-based samples who took part in studies conducted by the Queensland Institute for Medical Research Berghofer Medical Research Institute (QIMR), UK Biobank (UKB), Netherlands Twin Register (NTR), or QSkin Sun and Health Study (QSKIN) were included. Genome-wide association analysis and mendelian randomization (MR) were included. The study was conducted between 2016 and 2018.ExposuresPolygenic risk scores for schizophrenia derived from genetic data (genetic risk is independently measured from the occurrence of the disease). Socioeconomic status of the area was included as a moderator in some of the models.Main outcomes and measuresPopulation density of the place of residence of the participants determined from census data. Remoteness and socioeconomic status of the area were also tested.ResultsThe QIMR participants (15 544; 10 197 [65.6%] women; mean [SD] age, 54.4 [13.2] years) living in more densely populated areas (people per square kilometer) had a higher genetic loading for schizophrenia (r2 = 0.12%; P = 5.69 × 10-5), a result that was replicated across all 3 other cohorts (UKB: 345 246; 187 469 [54.3%] women; age, 65.7 [8.0] years; NTR: 11 212; 6727 [60.0%] women; age, 48.6 [17.5] years; and QSKIN: 15 726; 8602 [54.7%] women; age, 57.0 [7.9] years). This genetic association could account for 1.7% (95% CI, 0.8%-3.2%) of the schizophrenia risk. Estimates from MR analyses performed in the UKB sample were significant (b = 0.049; P = 3.7 × 10-7 using GSMR), suggesting that the genetic liability to schizophrenia may have a causal association with the tendency to live in urbanized locations.Conclusions and relevanceThe results of this study appear to support the hypothesis that individuals with increased genetic risk tend to live in urban/dense areas and suggest the need to refine the social stress model for schizophrenia by including genetics as well as possible gene-environment interactions.
| S-EPMC6142911 | biostudies-literature
Project description:C-reactive protein (CRP) has been indicated to be associated with the pathogenesis of schizophrenia (SZ) and other psychiatric disorders. The aim of this study is to investigate whether peripheral blood CRP levels are associated with the risk of SZ. We searched literature from databases of Pubmed, Embase and the Cochrane Library from inception to November 1, 2016 for studies that reported serum or plasma CRP levels in patients with SZ and non-SZ controls. At least two reviewers decided on eligibility and extracted data from included studies. Random effects meta-analyses were performed using standardized mean difference (SMD) as the effect estimate of the differences in CRP levels between subjects with SZ and healthy controls. We identified 18 studies representing 1963 patients with SZ and 3683 non-SZ controls. Compared with non-schizophrenics, blood CRP levels were moderately increased in people with SZ (SMD 0.53, 95% CI 0.30 to 0.76) irrespective of study region, sample size of included studies, patient mean age, age of SZ onset and patient body mass index. Publication bias was not detected through Egger's linear regression test (P = 0.292). We noticed that patients in Asia or Africa (n = 6, SMD 0.73, 95% CI 0.26 to 1.21) and whose age less than 30 years (n = 5, SMD 0.76, 95% CI 0.07 to 1.58) had substantially higher CRP levels. Our study provides evidence that higher CRP levels are associated with increased risk of SZ, especially for young adult patients less than 30 years. Further large-scale studies are strongly warranted to further confirm this association.
| S-EPMC5650435 | biostudies-other
Project description:Importance:Schizophrenia is a highly heritable psychiatric disorder, and recent studies have suggested that exposure to nitrogen dioxide (NO2) during childhood is associated with an elevated risk of subsequently developing schizophrenia. However, it is not known whether the increased risk associated with NO2 exposure is owing to a greater genetic liability among those exposed to highest NO2 levels. Objective:To examine the associations between childhood NO2 exposure and genetic liability for schizophrenia (as measured by a polygenic risk score), and risk of developing schizophrenia. Design, Setting, and Participants:Population-based cohort study including individuals with schizophrenia (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code F20) and a randomly selected subcohort. Using national registry data, all individuals born in Denmark between May 1, 1981, and December 31, 2002, were followed up from their 10th birthday until the first occurrence of schizophrenia, emigration, death, or December 31, 2012, whichever came first. Statistical analyses were conducted between October 24, 2018, and June 17, 2019. Exposures:Individual exposure to NO2 during childhood estimated as mean daily exposure to NO2 at residential addresses from birth to the 10th birthday. Polygenic risk scores were calculated as the weighted sum of risk alleles at selected single-nucleotide polymorphisms based on genetic material obtained from dried blood spot samples from the Danish Newborn Screening Biobank and on the Psychiatric Genomics Consortium genome-wide association study summary statistics file. Main Outcomes and Measures:The main outcome was schizophrenia. Weighted Cox proportional hazards regression models were fitted to estimate adjusted hazard ratios (AHRs) for schizophrenia with 95% CIs according to the exposures. Results:Of a total of 23?355 individuals, 11?976 (51.3%) were male and all had Danish-born parents. During the period of the study, 3531 were diagnosed with schizophrenia. Higher polygenic risk scores were correlated with higher childhood NO2 exposure (??=?0.0782; 95% CI, 0.065-0.091; P?<?.001). A 10-?g/m3 increase in childhood daily NO2 exposure (AHR, 1.23; 95% CI, 1.15-1.32) and a 1-SD increase in polygenic risk score (AHR, 1.29; 95% CI, 1.23-1.35) were independently associated with increased schizophrenia risk. Conclusions and Relevance:These findings suggest that the apparent association between NO2 exposure and schizophrenia is only slightly confounded by a higher polygenic risk score for schizophrenia among individuals living in areas with greater NO2. The findings demonstrate the utility of including polygenic risk scores in epidemiologic studies.
| S-EPMC6827271 | biostudies-literature
Project description: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.
| S-EPMC6583664 | biostudies-literature
Project description:Schizophrenia is a polygenic disorder with many genomic regions contributing to schizophrenia risk. The majority of genetic variants associated with schizophrenia lie in the non-coding genome and are thought to contribute to transcriptional regulation. Extensive transcriptomic dysregulation has been detected from postmortem brain samples of schizophrenia-affected individuals. However, the relationship between schizophrenia genetic risk factors and transcriptomic features has yet to be explored. Herein, we examined whether varying gene expression features, including differentially expressed genes (DEGs), co-expression networks, and central hubness of genes, contribute to the heritability of schizophrenia. We leveraged quantitative trait loci and chromatin interaction profiles to identify schizophrenia risk variants assigned to the genes that represent different transcriptomic features. We then performed stratified linkage disequilibrium score regression analysis on these variants to estimate schizophrenia heritability enrichment for different gene expression features. Notably, DEGs and co-expression networks showed nominal heritability enrichment. This nominal association can be partly explained by cellular heterogeneity, as DEGs were associated with the genetic risk of schizophrenia in a cell type-specific manner. Moreover, DEGs were enriched for target genes of schizophrenia-associated transcription factors, suggesting that the transcriptomic signatures of schizophrenia are the result of transcriptional regulatory cascades elicited by genetic risk factors.
| S-EPMC8304922 | biostudies-literature
Project description:The author previously described a theoretical cause of schizophrenia based on the effects of estrogenic endocrine disruption. In the current review, the author describes how increased estrogen during pregnancy increases susceptibility to certain viral infections associated with increased risk for schizophrenia. The review further discusses how prenatal estrogen exposure could explain associations of schizophrenia with autoimmune diseases, urban environments, and stress. Based on the association of increased estrogen with schizophrenia risk factors, the author proposes increased prenatal estrogen as a unifying factor, perhaps the primary event, in the etiology of schizophrenia.
| S-EPMC3160212 | biostudies-literature