Common schizophrenia alleles are enriched in mutation-intolerant genes and in regions under strong background selection

Schizophrenia is a debilitating psychiatric condition often associated with poor quality of life and decreased life expectancy. Lack of progress in improving treatment outcomes has been attributed to limited knowledge of the underlying biology, although large-scale genomic studies have begun to provide insights. We report a new genome-wide association study of schizophrenia (11,260 cases and 24,542 controls), and through meta-analysis with existing data we identify 50 novel associated loci and 145 loci in total. Through integrating genomic fine-mapping with brain expression and chromosome conformation data, we identify candidate causal genes within 33 loci. We also show for the first time that the common variant association signal is highly enriched among genes that are under strong selective pressures. These findings provide new insights into the biology and genetic architecture of schizophrenia, highlight the importance of mutation-intolerant genes and suggest a mechanism by which common risk variants persist in the population.

Modeling Linkage Disequilibrium Increases Accuracy of Polygenic Risk Scores

Polygenic risk scores have shown great promise in predicting complex disease risk and will become more accurate as training sample sizes increase. The standard approach for calculating risk scores involves linkage disequilibrium (LD)-based marker pruning and applying a p value threshold to association statistics, but this discards information and can reduce predictive accuracy. We introduce LDpred, a method that infers the posterior mean effect size of each marker by using a prior on effect sizes and LD information from an external reference panel. Theory and simulations show that LDpred outperforms the approach of pruning followed by thresholding, particularly at large sample sizes. Accordingly, predicted R(2) increased from 20.1% to 25.3% in a large schizophrenia dataset and from 9.8% to 12.0% in a large multiple sclerosis dataset. A similar relative improvement in accuracy was observed for three additional large disease datasets and for non-European schizophrenia samples. The advantage of LDpred over existing methods will grow as sample sizes increase.

Partitioning heritability of regulatory and cell-type-specific variants across 11 common diseases

Regulatory and coding variants are known to be enriched with associations identified by genome-wide association studies (GWASs) of complex disease, but their contributions to trait heritability are currently unknown. We applied variance-component methods to imputed genotype data for 11 common diseases to partition the heritability explained by genotyped SNPs (hg(2)) across functional categories (while accounting for shared variance due to linkage disequilibrium). Extensive simulations showed that in contrast to current estimates from GWAS summary statistics, the variance-component approach partitions heritability accurately under a wide range of complex-disease architectures. Across the 11 diseases DNaseI hypersensitivity sites (DHSs) from 217 cell types spanned 16% of imputed SNPs (and 24% of genotyped SNPs) but explained an average of 79% (SE = 8%) of hg(2) from imputed SNPs (5.1× enrichment; p = 3.7 × 10(-17)) and 38% (SE = 4%) of hg(2) from genotyped SNPs (1.6× enrichment, p = 1.0 × 10(-4)). Further enrichment was observed at enhancer DHSs and cell-type-specific DHSs. In contrast, coding variants, which span 1% of the genome, explained <10% of hg(2) despite having the highest enrichment. We replicated these findings but found no significant contribution from rare coding variants in independent schizophrenia cohorts genotyped on GWAS and exome chips. Our results highlight the value of analyzing components of heritability to unravel the functional architecture of common disease.

Estimation of Genetic Correlation via Linkage Disequilibrium Score Regression and Genomic Restricted Maximum Likelihood

Genetic correlation is a key population parameter that describes the shared genetic architecture of complex traits and diseases. It can be estimated by current state-of-art methods, i.e., linkage disequilibrium score regression (LDSC) and genomic restricted maximum likelihood (GREML). The massively reduced computing burden of LDSC compared to GREML makes it an attractive tool, although the accuracy (i.e., magnitude of standard errors) of LDSC estimates has not been thoroughly studied. In simulation, we show that the accuracy of GREML is generally higher than that of LDSC. When there is genetic heterogeneity between the actual sample and reference data from which LD scores are estimated, the accuracy of LDSC decreases further. In real data analyses estimating the genetic correlation between schizophrenia (SCZ) and body mass index, we show that GREML estimates based on ∼150,000 individuals give a higher accuracy than LDSC estimates based on ∼400,000 individuals (from combined meta-data). A GREML genomic partitioning analysis reveals that the genetic correlation between SCZ and height is significantly negative for regulatory regions, which whole genome or LDSC approach has less power to detect. We conclude that LDSC estimates should be carefully interpreted as there can be uncertainty about homogeneity among combined meta-datasets. We suggest that any interesting findings from massive LDSC analysis for a large number of complex traits should be followed up, where possible, with more detailed analyses with GREML methods, even if sample sizes are lesser.

Evaluating Sex and Age Differences in ADI-R and ADOS Scores in a Large European Multi-site Sample of Individuals with Autism Spectrum Disorder

Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and repetitive behaviours were lower in females than males, alongside comparable levels of social interaction and communication difficulties in females and males. Current ADI-R and ADOS scores showed no sex differences for ASD severity. There were lower socio-communicative symptoms in older compared to younger individuals. This large European ASD sample adds to the literature on sex and age variations of ASD symptomatology.

A Genetics-First Approach to Dissecting the Heterogeneity of Autism: Phenotypic Comparison of Autism Risk Copy Number Variants

OBJECTIVE

Certain copy number variants (CNVs) greatly increase the risk of autism. The authors conducted a genetics-first study to investigate whether heterogeneity in the clinical presentation of autism is underpinned by specific genotype-phenotype relationships.

METHODS

This international study included 547 individuals (mean age, 12.3 years [SD=4.2], 54% male) who were ascertained on the basis of having a genetic diagnosis of a rare CNV associated with high risk of autism (82 16p11.2 deletion carriers, 50 16p11.2 duplication carriers, 370 22q11.2 deletion carriers, and 45 22q11.2 duplication carriers), as well as 2,027 individuals (mean age, 9.1 years [SD=4.9], 86% male) with autism of heterogeneous etiology. Assessments included the Autism Diagnostic Interview-Revised and IQ testing.

RESULTS

The four genetic variant groups differed in autism symptom severity, autism subdomain profile, and IQ profile. However, substantial variability was observed in phenotypic outcome in individual genetic variant groups (74%-97% of the variance, depending on the trait), whereas variability between groups was low (1%-21%, depending on the trait). CNV carriers who met autism criteria were compared with individuals with heterogeneous autism, and a range of profile differences were identified. When clinical cutoff scores were applied, 54% of individuals with one of the four CNVs who did not meet full autism diagnostic criteria had elevated levels of autistic traits.

CONCLUSIONS

Many CNV carriers do not meet full diagnostic criteria for autism but nevertheless meet clinical cutoffs for autistic traits. Although profile differences between variants were observed, there is considerable variability in clinical symptoms in the same variant.

Sex differences in autism spectrum disorders: does sex moderate the pathway from clinical symptoms to adaptive behavior?

We explored sex differences in diagnostic categories, clinical symptoms and adaptive behavior of persons with autism spectrum disorders, as well as sex-specific correlations of clinical and adaptive caracteristics. The study involved 108 patients (83 males, 6.73 ± 4.33 years old) diagnosed with autism spectrum disorders (ASD). Assessment included ADI-R and Vineland Adaptive Behavior Scale II. Males were more often diagnosed with typical autism. There were no sex differences in the autistic symptoms, while females showed better functioning in Daily living skills, without reaching statistically significant difference (p = 0.062). We have found different associations of autistic symptoms with different aspects of adaptive behavior in males and females. Social reciprocity in females correlated with social domain of adaptive behavior, in a positive direction. Our findings have shown that although there are no sex differences in autistic symptoms, females tend to be somewhat more functional, and are also less frequently diagnosed with typical autism. Our results have also shown that sex might moderate the way clinical symptoms are expressed in adaptive behavior. Social reciprocity might be the core feature regarding sex differences in ASD. Our findings might have diagnostic and therapeutical implications, pointing out to the need for individualized, sex-specific treatment in this group of disorders.

Dopamine in Autism Spectrum Disorders-Focus on D2/D3 Partial Agonists and Their Possible Use in Treatment

Autism spectrum disorders (ASD) are a group of disorders characterized by impairment in social communication and repetitive and stereotyped behaviors. ASD etiology is very complex, including the effect of both genetic and environmental factors. So far, no specific treatment for the core symptoms of ASD has been developed, although attempts have been made for the treatment of repetitive behavior. The pharmacological treatment is aimed at treating non-specific symptoms such as irritability and aggression. Recent studies pointed out to the possible role of altered dopamine signaling in mesocorticolimbic and nigrostriatal circuits in ASD. In addition, several research pointed out to the association of dopamine receptors polymorphism and ASD, specifically repetitive and stereotyped behavior. In this paper, we will provide a review of the studies regarding dopamine signaling in ASD, existing data on the effects of D2/D3 partial agonists in ASD, possible implications regarding their individual receptor profiles, and future perspectives of their possible use in ASD treatment.

Autism Spectrum Disorders and Perinatal Complications-Is Oxidative Stress the Connection?

Background: Autism spectrum disorders (ASD) are complex psychiatric disorders, with gene environment interaction being in the basis of their etiology. The association of perinatal complications and ASD is well established. Recent findings suggested that oxidative stress and polymorphism in genes encoding antioxidant enzymes might be involved in the development of ASD. Glutathione transferases (GSTs) have an important role in the antioxidant defense system. We aimed to establish whether the predictive effects of prenatal and perinatal complications (as possible oxidative stress inducers) on ASD risk are dependent on GST polymorphisms. Methods: The study included 113 ASD cases and 114 age- and sex group-matched healthy controls. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The questionnaire regarding prenatal and perinatal risk factors and complications was administered for all the subjects in the study. Results: The evaluated perinatal complications as a group significantly increased the risk of ASD [odds ratio (OR) = 9.415; p = 0.000], as well as individual perinatal complications, such as prematurity (OR = 11.42; p = 0.001), neonatal jaundice (OR = 8.774; p = 0.000), respiratory distress syndrome (OR = 4.835; p = 0.047), and the use of any medication during pregnancy (OR = 2.413; p = 0.03). In logistic regression model, adding GST genotypes did not modify the significant effects found for prematurity and neonatal jaundice as risk factors in ASD. However, there was a significant interaction of GST genotype with medication use during pregnancy and the use of tocolytics during pregnancy, which was predictive of ASD risk only in carriers of GSTM1-null, as opposed to carriers of GSTM1-active genotype. Conclusion: Specific perinatal complications may be significant risk factors for ASD. GSTM1 genotype may serve as a moderator of the effect of some prenatal factors on the risk of ASD such as using medication during pregnancy. It may be speculated that different oxidative stress-related genetic and environmental factors could lead to development of ASD. Apart from etiological mechanisms, possible therapeutic implications in ASD are also discussed.

Epilepsy and interictal epileptiform activity in patients with autism spectrum disorders

PURPOSE

The purpose of this study was to determine the prevalence of epilepsy and subclinical epileptiform abnormalities in children with autism spectrum disorder (ASD), and to investigate its effects on core autistic symptoms and adaptive behavior skills.

METHODS

Patients with diagnosis of ASD who met full criteria on Autism Diagnostic Interview-Revised (ADI-R) were included in the study. Adaptive behavior skills were assessed by Vineland Adaptive Behavior Scale-II (VABS-II). Clinical assessment for epilepsy and video electroencephalography (EEG) (v-EEG) examinations during wakefulness and/or sleep were prospectively performed in all patients.

RESULTS

A total of 112 patients with diagnosis of ASD of mean age 6.58 ± 3.72 were included in the study. Based on clinical and v-EEG assessments, three groups of patients were defined: 1) patients with epilepsy (n = 17; 15.2%); 2) patients with epileptiform discharges in absence of clinical seizures (n = 14; 12.5%); 3) patients without epilepsy and without epileptiform discharges (n = 81; 72.3%). There were no significant differences between three groups of patients on ADI-R subscores. Speech development was also not significantly related to epilepsy. There was a slight tendency of the VABS-II motor skills score to be higher in the group of patients with autism without clinical diagnosis of epilepsy and without subclinical epileptiform discharges (p < 0.05) in comparison with the two other groups. According to this tendency, we might claim that patients with higher scores on motor skills could have 0.88 times lower odds for having epileptiform EEG activity.

CONCLUSIONS

According to our results, we were not able to detect differences in the ADI-R between the three populations with ASD, all with unknown etiology. Epilepsy, as well as subclinical epileptic discharges, showed small effects on Motor Skills in patients with autism, and had no effect on adaptive behavior Communication/Socialization/Daily Living Skills.

Coping strategies in civilians during air attacks

BACKGROUND

Coping strategies may influence the psychological outcome after a stressful event, both as coping at the time of the event and as strategies of dealing with its consequences after the event. The aim of the study was to investigate coping strategies used by civilians during the air attacks in Yugoslavia in 1999, and their association with the level of exposure, gender and psychological symptoms 1 year later.

METHOD

The sample is a non-selective group of 139 medical students from the University of Belgrade, Yugoslavia. Open questions and content analysis were used to assess coping strategies. Symptoms of intrusion and avoidance were assessed, as well as general psychological symptoms.

RESULTS

Content analysis of answers to open questions revealed nine categories of coping strategies (sport and walks, leisure activities, talking and gathering, humor, avoidance, philosophical approach, getting information, work, and substance abuse). A cluster analysis identified three groups of students with different styles of coping. Students that used dominantly 'talking and gathering' had the highest, and the ones that mostly used 'leisure activities' the lowest scores on intrusion. There were significant gender differences in how coping strategies were associated with intrusive symptoms.

CONCLUSION

The type of coping strategies used during the air attacks may contribute to the level of intrusive symptoms 1 year after the event. Different coping strategies might be effective in men and women to reduce intrusive symptoms. Longitudinal and prospective studies are needed to draw definite conclusions on causal relationships between coping strategies and levels of posttraumatic stress.

Publisher Correction: Common schizophrenia alleles are enriched in mutation-intolerant genes and in regions under strong background selection

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Serbian Language version of the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up: Cross-Cultural Adaptation and Assessment of Reliability

Early detection of Autism Spectrum Disorder (ASD) has proven to be of high significance, however there is a limited availability of ASD screening tools in Serbian language. In this study we aim to translate, assess reliability and, in part, test the applicability of Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT R/F) in Serbian Healthcare environment. We screened 128 children in three primary healthcare centres and 20 children in a tertiary psychiatric center, using M-CHAT R/F translated into Serbian language, between December 2014 and October 2015. At the end of the screening process 80% of participants in the risk group screened positive for ASD, while in the control group 4 (3.1%) participants screened positive, with a mean total scores of 8.25 and 0.66 respectively. The Cronbach’s α coefficient was 0.91 and Guttman’s λ6 was 0.93. Test – retest reliability was deemed as acceptable, and no significant correlation was found between M-CHAT-R/F scores and Epworth Sleepiness Scale for children scores. The Serbian version of the M-CHAT-R/F has shown satisfactory reliability. We can therefore assert that it is a reliable tool for identifying ASD and it can be used in clinical practice to improve early detection, assessment and treatment.

Determinants of quality of life among individuals seeking mental health care after termination of state of emergency due to the coronavirus disease 2019 pandemic

ABSTRACT

Prompted by the need to measure the impact of the coronavirus disease 2019 on main areas of quality of life related to mental health (MH), the COV-19-impact on quality of life (COV19-QoL) scale has been developed recently. We measured how patients seeking face-to-face MH care perceived the coronavirus disease 2019 impact on QoL and how socio-demographic factors, stress, and personality contributed to QoL in this diagnostically diverse population.Patients aged 18 to 65 years (n = 251) who came for the first time to the outpatient units during the 6-week index-period (May 21-July 1, 2020) were included. The cross-sectional assessment involved sociodemographic variables, working diagnosis, personality traits (7-dimension model, including HEXACO and DELTA), stress (list of threatening experiences and proximity to virus), and COV19-QoL.The perceived impact of the pandemic on QoL was above the theoretical mean of a 5-point scale (COV19-Qol = 3.1 ± 1.2). No association between total COV19-QoL score, sociodemographic parameters, and working diagnoses was found in the present sample. After testing whether positional (threatening experiences), or dispositional (personality) factors were predominant in the perceived impact of COV-19 on QoL, significant predictors of the outcome were personality traits Disintegration (B = 0.52; P < .01) and Emotionality (B = 0.18; P < .05).It seems that pervasiveness and uncertainty of the pandemic threat triggers-especially in those high on Disintegration trait-a chain of mental events with the decrease of QoL as a final result. Present findings could be used to establish a profile of MH help seeking population in relation to this biological disaster, and to further explore QoL and personality in different contexts.

Glutathione S-Transferase Polymorphisms and Clinical Characteristics in Autism Spectrum Disorders

Background: Autism spectrum disorders (ASD) are a heterogeneous group of developmental disorders, with different levels of symptoms, functioning, and comorbidities. Recent findings suggested that oxidative stress and genetic variability in glutathione S-transferases (GSTs) might increase the risk of ASD development. We aimed to determine whether GST polymorphisms influence the severity of symptoms as well as the cognitive and adaptive abilities in children with ASD. Methods: The sample included 113 ASD cases. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The clinical characteristics were determined with Autism Diagnostic Interview-Revised (ADI-R) in all of the participants. In non-verbal participants, we explored the adaptive functioning using the Vineland Adaptive Behavior Scale II, while in verbal participants, we used the Wechsler Abbreviated Scale of Intelligence (WASI). Results: It was shown that the GSTA1 * CC genotype was a predictor of a lower non-verbal communication impairment as well as of a lower chance of having seizures during life. GSTM1-active genotype predicted a higher adaptive functioning. The predictive effect of GSTA1, GSTM1, and GSTT1 genotype was moderated by exposure during pregnancy (maternal smoking and medication). The GSTP1 * IleIle genotype was significantly associated to a better cognitive functioning in children with ASD. Conclusion: Besides the complex gene-environment interaction for the specific risk of developing ASD, there is also a possible complexity of interactions between genetic and environmental factors influencing the level of symptoms and impairment in people with ASD. Detoxification and antioxidant enzymes, such as GSTA1, might contribute to the core of this complexity.

Positive Effects of the Caregiver Skill Training Program on Children With Developmental Disabilities: Experiences From Serbia

BACKGROUND

Intervention programs for children with developmental disabilities increasingly target caregiver training to implement effective strategies for child development. Research conducted in different countries shows that the Caregiver Skills Training Program (CST) developed by the World Health Organization and Autism Speaks could also be a recommended intervention.

METHODS

The pre-pilot phase included seven, and the pilot phase included 29 families of children with developmental disabilities trained to implement the intervention program. The caregivers were asked to complete the Autism Treatment Evaluation Checklist at the beginning and at the end of the program.

RESULTS

In the pre-pilot phase, the Wilcoxon signed-rank test determined a statistically significant improvement in Speech, Language and Communication (z = -2.99, p < 0.05) and Health/Physical/Behavior (z = -2.375, p < 0.05) after caregiver participation in the training program. In the pilot phase, the paired t-test also determined a statistically significant improvement in Speech, Language and Communication between the first (M = 24.52, SD = 5.57) and the second testing (M = 25.66, SD = 6.11), t₍₂₈₎ = -2.29, p < 0.05, as well as a significant improvement between the first (M = 36.62; SD = 7.15) and the second testing (M = 35.38; SD = 5.91), t₍₂₈₎ = 2.11, p < 0.05 in Health/Physical/Behavior. Eta squared values (0.16 and 0.14) indicate that the intervention effect was significant. No differences were determined in Sociability and Sensory/Cognitive Awareness between the first and the second testing.

CONCLUSION

The initial results of the Caregiver Skills Training Program are encouraging. For this program to be recommended as an evidence-based intervention, further research should be conducted on larger samples, controlling possible intervening variables.