Genetics evaluation for the etiologic diagnosis of autism spectrum disorders

Identification and Analysis of ZIC-Related Genes in Cerebellum of Autism Spectrum Disorders

Objective

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with significant genetic heterogeneity. The ZIC gene family can regulate neurodevelopment, especially in the cerebellum, and has been implicated in ASD-like behaviors in mice. We performed bioinformatic analysis to identify the ZIC gene family in the ASD cerebellum.

Methods

We explored the roles of ZIC family genes in ASD by investigating (i) the association of ZIC genes with ASD risk genes from the Simons Foundation Autism Research Initiative (SFARI) database and ZIC genes in the brain regions of the Human Protein Atlas (HPA) database; (ii) co-expressed gene networks of genes positively and negatively correlated with ZIC1, ZIC2, and ZIC3, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and receiver operating characteristic (ROC) curve analysis of genes in these networks; and (iii) the relationship between ZIC1, ZIC2, ZIC3, and their related genes with cerebellar immune cells and stromal cells in ASD patients.

Results

(i) ZIC1, ZIC2, and ZIC3 were associated with neurodevelopmental disorders and risk genes related to ASD in the human cerebellum and (ii) ZIC1, ZIC2, and ZIC3 were highly expressed in the cerebellum, which may play a pathogenic role by affecting neuronal development and the cerebellar internal environment in patients with ASD, including immune cells, astrocytes, and endothelial cells. (iii) OLFM3, SLC27A4, GRB2, TMED1, NR2F1, and STRBP are closely related to ZIC1, ZIC2, and ZIC3 in ASD cerebellum and have good diagnostic accuracy. (iv) ASD mice in the maternal immune activation model demonstrated that Zic3 and Nr2f1 levels were decreased in the immune-activated cerebellum.

Conclusion

Our study supports the role of ZIC1, ZIC2, and ZIC3 in ASD pathogenesis and provides potential targets for early and accurate prediction of ASD.

Transcriptional Dysregulation and Impaired Neuronal Activity in FMR1 Knock-Out and Fragile X Patients' iPSC-Derived Models

Fragile X syndrome (FXS) is caused by a repression of the FMR1 gene that codes the Fragile X mental retardation protein (FMRP), an RNA binding protein involved in processes that are crucial for proper brain development. To better understand the consequences of the absence of FMRP, we analyzed gene expression profiles and activities of cortical neural progenitor cells (NPCs) and neurons obtained from FXS patients' induced pluripotent stem cells (IPSCs) and IPSC-derived cells from FMR1 knock-out engineered using CRISPR-CAS9 technology. Multielectrode array recordings revealed in FMR1 KO and FXS patient cells, decreased mean firing rates; activities blocked by tetrodotoxin application. Increased expression of presynaptic mRNA and transcription factors involved in the forebrain specification and decreased levels of mRNA coding AMPA and NMDA subunits were observed using RNA sequencing on FMR1 KO neurons and validated using quantitative PCR in both models. Intriguingly, 40% of the differentially expressed genes were commonly deregulated between NPCs and differentiating neurons with significant enrichments in FMRP targets and autism-related genes found amongst downregulated genes. Our findings suggest that the absence of FMRP affects transcriptional profiles since the NPC stage, and leads to impaired activity and neuronal differentiation over time, which illustrates the critical role of FMRP protein in neuronal development.

A rapid and dynamic role for FMRP in the plasticity of adult neurons

Fragile X syndrome (FXS) is a neuro-developmental disorder caused by silencing Fmr1, which encodes the RNA-binding protein FMRP. Although Fmr1 is expressed in adult neurons, it has been challenging to separate acute from chronic effects of loss of Fmr1 in models of FXS. We have used the precision of Drosophila genetics to test if Fmr1 acutely affects adult neuronal plasticity in vivo, focusing on the s-LNv circadian pacemaker neurons that show 24 hour rhythms in structural plasticity. We found that over-expressing Fmr1 for only 4 hours blocks the activity-dependent expansion of s-LNv projections without altering the circadian clock or activity-regulated gene expression. Conversely, acutely reducing Fmr1 expression prevented s-LNv projections from retracting. One FMRP target that we identified in s-LNvs is sif, which encodes a Rac1 GEF. Our data indicate that FMRP normally reduces sif mRNA translation at dusk to reduce Rac1 activity. Overall, our data reveal a previously unappreciated rapid and direct role for FMRP in acutely regulating neuronal plasticity in adult neurons, and underscore the importance of RNA-binding proteins in this process.

Elevated levels of FMRP-target MAP1B impair human and mouse neuronal development and mouse social behaviors via autophagy pathway

Fragile X messenger ribonucleoprotein 1 protein (FMRP) binds many mRNA targets in the brain. The contribution of these targets to fragile X syndrome (FXS) and related autism spectrum disorder (ASD) remains unclear. Here, we show that FMRP deficiency leads to elevated microtubule-associated protein 1B (MAP1B) in developing human and non-human primate cortical neurons. Targeted MAP1B gene activation in healthy human neurons or MAP1B gene triplication in ASD patient-derived neurons inhibit morphological and physiological maturation. Activation of Map1b in adult male mouse prefrontal cortex excitatory neurons impairs social behaviors. We show that elevated MAP1B sequesters components of autophagy and reduces autophagosome formation. Both MAP1B knockdown and autophagy activation rescue deficits of both ASD and FXS patients' neurons and FMRP-deficient neurons in ex vivo human brain tissue. Our study demonstrates conserved FMRP regulation of MAP1B in primate neurons and establishes a causal link between MAP1B elevation and deficits of FXS and ASD.

Epigenetic Gene-Regulatory Loci in Alu Elements Associated with Autism Susceptibility in the Prefrontal Cortex of ASD

Alu elements are transposable elements that can influence gene regulation through several mechanisms; nevertheless, it remains unclear whether dysregulation of Alu elements contributes to the neuropathology of autism spectrum disorder (ASD). In this study, we characterized transposable element expression profiles and their sequence characteristics in the prefrontal cortex tissues of ASD and unaffected individuals using RNA-sequencing data. Our results showed that most of the differentially expressed transposable elements belong to the Alu family, with 659 loci of Alu elements corresponding to 456 differentially expressed genes in the prefrontal cortex of ASD individuals. We predicted cis- and trans-regulation of Alu elements to host/distant genes by conducting correlation analyses. The expression level of Alu elements correlated significantly with 133 host genes (cis-regulation, adjusted p < 0.05) associated with ASD as well as the cell survival and cell death of neuronal cells. Transcription factor binding sites in the promoter regions of differentially expressed Alu elements are conserved and associated with autism candidate genes, including RORA. COBRA analyses of postmortem brain tissues showed significant hypomethylation in global methylation analyses of Alu elements in ASD subphenotypes as well as DNA methylation of Alu elements located near the RNF-135 gene (p < 0.05). In addition, we found that neuronal cell density, which was significantly increased (p = 0.042), correlated with the expression of genes associated with Alu elements in the prefrontal cortex of ASD. Finally, we determined a relationship between these findings and the ASD severity (i.e., ADI-R scores) of individuals with ASD. Our findings provide a better understanding of the impact of Alu elements on gene regulation and molecular neuropathology in the brain tissues of ASD individuals, which deserves further investigation.

Biochemical, Genetic and Clinical Diagnostic Approaches to Autism-Associated Inherited Metabolic Disorders

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders characterized by impaired social interaction, limited communication skills, and restrictive and repetitive behaviours. The pathophysiology of ASD is multifactorial and includes genetic, epigenetic, and environmental factors, whereas a causal relationship has been described between ASD and inherited metabolic disorders (IMDs). This review describes biochemical, genetic, and clinical approaches to investigating IMDs associated with ASD. The biochemical work-up includes body fluid analysis to confirm general metabolic and/or lysosomal storage diseases, while the advances and applications of genomic testing technology would assist with identifying molecular defects. An IMD is considered likely underlying pathophysiology in ASD patients with suggestive clinical symptoms and multiorgan involvement, of which early recognition and treatment increase their likelihood of achieving optimal care and a better quality of life.

The Autism Spectrum: Behavioral, Psychiatric and Genetic Associations

Autism spectrum disorder (ASD) consists of a group of heterogeneous genetic neurobehavioral disorders associated with developmental impairments in social communication skills and stereotypic, rigid or repetitive behaviors. We review common behavioral, psychiatric and genetic associations related to ASD. Autism affects about 2% of children with 4:1 male-to-female ratio and a heritability estimate between 70 and 90%. The etiology of ASD involves a complex interplay between inheritance and environmental factors influenced by epigenetics. Over 800 genes and dozens of genetic syndromes are associated with ASD. Novel gene–protein interactions with pathway and molecular function analyses have identified at least three functional pathways including chromatin modeling, Wnt, Notch and other signaling pathways and metabolic disturbances involving neuronal growth and dendritic spine profiles. An estimated 50% of individuals with ASD are diagnosed with chromosome deletions or duplications (e.g., 15q11.2, BP1-BP2, 16p11.2 and 15q13.3), identified syndromes (e.g., Williams, Phelan-McDermid and Shprintzen velocardiofacial) or single gene disorders. Behavioral and psychiatric conditions in autism impacted by genetics influence clinical evaluations, counseling, diagnoses, therapeutic interventions and treatment approaches. Pharmacogenetics testing is now possible to help guide the selection of psychotropic medications to treat challenging behaviors or co-occurring psychiatric conditions commonly seen in ASD. In this review of the autism spectrum disorder, behavioral, psychiatric and genetic observations and associations relevant to the evaluation and treatment of individuals with ASD are discussed.

Research Gaps in Fragile X Syndrome: An Updated Literature Review to Inform Clinical and Public Health Practice

OBJECTIVE

The phenotypic impact of fragile X syndrome (FXS) has been well-documented since the discovery of the fragile X messenger ribonucleoprotein 1 gene 30 years ago. However, gaps remain in clinical and public health research. The purpose of this literature review was to determine the extent to which these gaps have been addressed and identify targeted areas of future research.

METHODS

We conducted an electronic search of several scientific databases using a variety of key words. The search focused on 5 areas identified as research gaps by an earlier review: (1) diagnosis, (2) phenotypic presentation, (3) familial impact, (4) interventions and treatments, and (5) life span perspectives. Inclusion criteria included publication between 2014 and 2020, focus on human subjects, and publication in English. A total of 480 articles were identified, 365 were reviewed, and 112 are summarized in this review.

RESULTS

Results are organized into the following categories: (1) FXS phenotype and subtypes (FXS subtypes, medical profile, cognitive/developmental profile, social and behavioral profile); (2) needs of adults; (3) public health needs (clinical diagnosis and newborn screening, health care needs, and access); (4) treatment (treatment priorities, pharmacological treatments, and behavioral and educational interventions); and (5) families (economic burden and mother-child relationship).

CONCLUSION

Despite the progress in many areas of FXS research, work remains to address gaps in clinical and public health knowledge. We pose 3 main areas of focused research, including early detection and diagnosis, determinants of health, and development and implementation of targeted interventions.

Advanced paternal age diversifies individual trajectories of vocalization patterns in neonatal mice

Infant crying is a communicative behavior impaired in neurodevelopmental disorders (NDDs). Because advanced paternal age is a risk factor for NDDs, we performed computational approaches to evaluate how paternal age affected vocal communication and body weight development in C57BL/6 mouse offspring from young and aged fathers. Analyses of ultrasonic vocalization (USV) consisting of syllables showed that advanced paternal age reduced the number and duration of syllables, altered the syllable composition, and caused lower body weight gain in pups. Pups born to young fathers had convergent vocal characteristics with a rich repertoire, whereas those born to aged fathers exhibited more divergent vocal patterns with limited repertoire. Additional analyses revealed that some pups from aged fathers displayed atypical USV trajectories. Thus, our study indicates that advanced paternal age has a significant effect on offspring's vocal development. Our computational analyses are effective in characterizing altered individual diversity.

LINE-1 and Alu methylation signatures in autism spectrum disorder and their associations with the expression of autism-related genes

Long interspersed nucleotide element-1 (LINE-1) and Alu elements are retrotransposons whose abilities cause abnormal gene expression and genomic instability. Several studies have focused on DNA methylation profiling of gene regions, but the locus-specific methylation of LINE-1 and Alu elements has not been identified in autism spectrum disorder (ASD). Here we interrogated locus- and family-specific methylation profiles of LINE-1 and Alu elements in ASD whole blood using publicly-available Illumina Infinium 450 K methylation datasets from heterogeneous ASD and ASD variants (Chromodomain Helicase DNA-binding 8 (CHD8) and 16p11.2del). Total DNA methylation of repetitive elements were notably hypomethylated exclusively in ASD with CHD8 variants. Methylation alteration in a family-specific manner including L1P, L1H, HAL, AluJ, and AluS families were observed in the heterogeneous ASD and ASD with CHD8 variants. Moreover, LINE-1 and Alu methylation within target genes is inversely related to the expression level in each ASD variant. The DNA methylation signatures of the LINE-1 and Alu elements in ASD whole blood, as well as their associations with the expression of ASD-related genes, have been identified. If confirmed in future larger studies, these findings may contribute to the identification of epigenomic biomarkers of ASD.

The Emerging Roles of Long Non-Coding RNAs in Intellectual Disability and Related Neurodevelopmental Disorders

In the human brain, long non-coding RNAs (lncRNAs) are widely expressed in an exquisitely temporally and spatially regulated manner, thus suggesting their contribution to normal brain development and their probable involvement in the molecular pathology of neurodevelopmental disorders (NDD). Bypassing the classic protein-centric conception of disease mechanisms, some studies have been conducted to identify and characterize the putative roles of non-coding sequences in the genetic pathogenesis and diagnosis of complex diseases. However, their involvement in NDD, and more specifically in intellectual disability (ID), is still poorly documented and only a few genomic alterations affecting the lncRNAs function and/or expression have been causally linked to the disease endophenotype. Considering that a significant fraction of patients still lacks a genetic or molecular explanation, we expect that a deeper investigation of the non-coding genome will unravel novel pathogenic mechanisms, opening new translational opportunities. Here, we present evidence of the possible involvement of many lncRNAs in the etiology of different forms of ID and NDD, grouping the candidate disease-genes in the most frequently affected cellular processes in which ID-risk genes were previously collected. We also illustrate new approaches for the identification and prioritization of NDD-risk lncRNAs, together with the current strategies to exploit them in diagnosis.

Deficiency of the neurodevelopmental disorder-associated gene Cyfip2 alters the retinal ganglion cell properties and visual acuity

Intellectual disability (ID) is a neurodevelopmental disorder affecting approximately 0.5–3% of the population in the developed world. Individuals with ID exhibit deficits in intelligence, impaired adaptive behavior and often visual impairments. Cytoplasmic fragile X mental retardation 1 (FMR1)-interacting protein 2 (CYFIP2) is an interacting partner of the FMR protein, whose loss results in fragile X syndrome, the most common inherited cause of ID. Recently, CYFIP2 variants have been found in patients with early-onset epileptic encephalopathy, developmental delay and ID. Such individuals often exhibit visual impairments; however, the underlying mechanism is poorly understood. In the present study, we investigated the role of Cyfip2 in retinal and visual functions by generating and analyzing Cyfip2 conditional knockout (CKO) mice. While we found no major differences in the layer structures and cell compositions between the control and Cyfip2 CKO retinas, a subset of genes associated with the transporter and channel activities was differentially expressed in Cyfip2 CKO retinas than in the controls. Multi-electrode array recordings showed more sustained and stronger responses to positive flashes of the ON ganglion cells in the Cyfip2 CKO retina than in the controls, although electroretinogram analysis revealed that Cyfip2 deficiency unaffected the photoreceptor and ON bipolar cell functions. Furthermore, analysis of initial and late phase optokinetic responses demonstrated that Cyfip2 deficiency impaired the visual function at the organismal level. Together, our results shed light on the molecular mechanism underlying the visual impairments observed in individuals with CYFIP2 variants and, more generally, in patients with neurodevelopmental disorders, including ID.

FMR1 and Autism, an Intriguing Connection Revisited

Autism Spectrum Disorder (ASD) represents a distinct phenotype of behavioral dysfunction that includes deficiencies in communication and stereotypic behaviors. ASD affects about 2% of the US population. It is a highly heritable spectrum of conditions with substantial genetic heterogeneity. To date, mutations in over 100 genes have been reported in association with ASD phenotypes. Fragile X syndrome (FXS) is the most common single-gene disorder associated with ASD. The gene associated with FXS, FMR1 is located on chromosome X. Accordingly, the condition has more severe manifestations in males. FXS results from the loss of function of FMR1 due to the expansion of an unstable CGG repeat located in the 5'' untranslated region of the gene. About 50% of the FXS males and 20% of the FXS females meet the Diagnostic Statistical Manual 5 (DSM-5) criteria for ASD. Among the individuals with ASD, about 3% test positive for FXS. FMRP, the protein product of FMR1, is a major gene regulator in the central nervous system. Multiple pathways regulated by FMRP are found to be dysfunctional in ASD patients who do not have FXS. Thus, FXS presents the opportunity to study cellular phenomena that may have wider applications in the management of ASD and to develop new strategies for ASD therapy.

The molecular biology of FMRP: new insights into fragile X syndrome

Fragile X mental retardation protein (FMRP) is the product of the fragile X mental retardation 1 gene (FMR1), a gene that - when epigenetically inactivated by a triplet nucleotide repeat expansion - causes the neurodevelopmental disorder fragile X syndrome (FXS). FMRP is a widely expressed RNA-binding protein with activity that is essential for proper synaptic plasticity and architecture, aspects of neural function that are known to go awry in FXS. Although the neurophysiology of FXS has been described in remarkable detail, research focusing on the molecular biology of FMRP has only scratched the surface. For more than two decades, FMRP has been well established as a translational repressor; however, recent whole transcriptome and translatome analyses in mouse and human models of FXS have shown that FMRP is involved in the regulation of nearly all aspects of gene expression. The emerging mechanistic details of the mechanisms by which FMRP regulates gene expression may offer ways to design new therapies for FXS.

Inequities in diagnosis of Fragile X syndrome in Colombia

BACKGROUND

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and autism spectrum disorder (ASD). In Colombia, there are no screening or testing protocols established for the diagnosis of FXS. In this study, we aimed to describe the diagnostic trends of FXS in Colombia.

METHODS

Data were included on 1322 individuals obtained based on data from the only 2 databases available. Sociodemographic information and data related to the diagnostic process were obtained and included in this study.

RESULTS

The average age at the time of diagnosis for individuals with the full mutation (FM) was of 26.9 ± 2.57 years and was strongly dependent on sex and socioeconomic status. Most individuals with a molecular diagnosis were from the main cities.

CONCLUSION

The overall age of diagnosis of FXS is later in life than reports from other countries. Restricted access to molecular testing through the national health system might explain this discrepancy in Colombia.

Establishment of FXS-A9 panel with a single human X chromosome from fragile X syndrome-associated individual

Fragile X syndrome (FXS) is the most common inheritable form of intellectual disability. FMR1, the gene responsible for FXS, is located on human chromosome Xq27.3 and contains a stretch of CGG trinucleotide repeats in its 5' untranslated region. FXS is caused by CGG repeats that expand beyond 200, resulting in FMR1 silencing via promoter hypermethylation. The molecular mechanism underlying CGG repeat expansion, a fundamental cause of FXS, remains poorly understood, partly due to a lack of experimental systems. Accumulated evidence indicates that the large chromosomal region flanking a CGG repeat is critical for repeat dynamics. In the present study, we isolated and introduced whole human X chromosomes from healthy, FXS premutation carriers, or FXS patients who carried disease condition-associated CGG repeat lengths, into mouse A9 cells via microcell-mediated chromosome transfer. The CGG repeat length-associated methylation status and human FMR1 expression in these monochromosomal hybrid cells mimicked those in humans. Thus, this set of A9 cells containing CGG repeats from three different origins (FXS-A9 panel) may provide a valuable resource for investigating a series of genetic and epigenetic CGG repeat dynamics during FXS pathogenesis.

An Investigation of the Dynamic Thiol/Disulfide Homeostasis, As a Novel Oxidative Stress Plasma Biomarker, in Children With Autism Spectrum Disorders

We aimed to investigate the role of impaired oxidant-antioxidant homeostasis on the etiopathogenesis of autism with a novel oxidative stress (OS) marker, dynamic thiol/disulfide homeostasis (DTDH), and relationship between the symptom severity and markers. A total of 60 children with ASD aged 3-10 years and 54 unaffected children were investigated for the plasma DTDH parameters. A sociodemographic-data form, K-SADS-PL, Childhood Autism Rating Scale, Abnormal Behavior Checklist, Autism Behavior Checklist, and a developmentally appropriate IQ test were administered to all participants. Distortion of DTDH to the OS-side in the autism group was determined with lower plasma levels of native and total thiol, in contrast to a higher disulfide and thiol oxidation-reduction ratio. However, biomarkers had no correlation with the symptom severity of autism. Cutoff values for each parameter on the ROC curve might be useful to predict ASD and each DTDH biomarker was detected as an independent predictor of ASD. The present study demonstrated a disturbed redox status and absence of an expected compensatory increase in antioxidant response in a pediatric sample of ASD by measuring dynamic oxidation/reduction shifts with a novel, practical and reproducible analytical technique, and contributes to data regarding oxidative hypothesis on autism and raises the question of the place of antioxidants in autism treatment. Our results may suggest predictive usefulness of the plasma DTDH biomarkers in ASD, despite the study being conducted with a modestly small sample size that makes further research with a larger replication sample necessary to substantiate the findings. LAY SUMMARY: Dynamic thiol/disulfide homeostasis is a novel plasma marker used to determine the oxidative stress which is a natural result of disequilibrium between the oxidants and antioxidants in the human body. There is increasing interest regarding a central biological linking role of oxidative stress among the other etiological factors of autism. Our findings on the disturbed plasma dynamic thiol/disulfide homeostasis in children with autism and the absence of an expected antioxidant response against increased oxidative stress supports the data concerning the role of oxidative stress on the etiology of autism and the need of further research on the place of antioxidants in autism treatment.

Coexistence of Fragile-X Syndrome, 8p23.1 Deletion, and Balanced Translocation t(7;10)(p10;q24) in a Single Family

Aims: Fragile-X syndrome (FXS) is the most common inherited form of intellectual disability; it is caused by an abnormal CGG-repeat expansion at the FMR1 gene. However, a few cases of girls with mutations in the FMR1 gene have been reported in the literature. In this study, we describe the clinical and genetic assessment of a family who exhibits the unusual coexistence of FXS, an 8p23.1 deletion, and balanced translocation t(7;10)(p10;q24) in multiple members, including a symptomatic girl with FXS. Materials and Methods: All of the family members underwent comprehensive clinical and neurological examinations. All members of the family were also molecularly diagnosed using a combination of fluorescent-polymerase chain reaction (PCR), Triplet Repeat Primed-PCR, capillary electrophoresis, and karyotyping. Results: We identified a male proband and a female patient that presented with the craniofacial characteristics of FXS, neuropsychomotor developmental delay, speech delay, intellectual deficit, and a positive molecular diagnosis of FXS. Interestingly, the female patient presented with a severe phenotype also associated with the presence of 8p23.1 deletion, while the proband patient presented a balanced translocation t(7;10)(p10;q24). Moreover, we detected multiple carriers of the FXS premutation in the family. Conclusions: To our knowledge, we describe for the first time the simultaneous occurrence of FXS and an 8p23.1 deletion and their possible synergistic effects on the phenotype of a female patient. Moreover, we describe the coexistence of FXS, an 8p23.1 deletion, and a balanced translocation t(7;10)(p10;q24) in the same family.

Oxidative stress, metabolic and mitochondrial abnormalities associated with autism spectrum disorder

Autism spectrum disorder is a neurodevelopmental disorder characterized by impaired development and by abnormal function in regards to social interaction, communication and restricted, repetitive behavior. It affects approximately 1% of the worldwide population. Like other psychiatric disorders the diagnosis is based on observation of, and interview with the patient and next of kin, and diagnostic tests. Many genes have been associated with autism, but only few highly penetrant. Some researchers have instead focused on oxidative stress, metabolic abnormalities and mitochondrial dysfunction as an explanation of the disorder. Currently no cure exists for the disorder, making these abnormalities interesting as they are possibly correctable with supplements or treatment. These various processes cannot be seen independently as they are influencing and interacting with each other. Furthermore many of the metabolic changes seen in autism have also been shown in other psychiatric disorders such as attention deficit hyperactivity disorder, schizophrenia and bipolar disorder along with often comorbid disorders like epilepsy and intellectual disability. As such some of these abnormalities are not specific, however, could indicate a similar mechanism for the development of these disorders, with symptomatology and severity varying according to the location and the amount of damage done to proteins, cells and DNA. Clinical studies trying to treat these abnormalities, have widely been successful in correcting the metabolic abnormalities seen, but only some studies have also shown bettering of autistic symptoms. Hopefully with increased knowledge of the pathophysiology of the disorder, future preventive measures or treatment can be developed.

Recent Advances in Understanding the Genetic Architecture of Autism

Recent advances in understanding the genetic architecture of autism spectrum disorder have allowed for unprecedented insight into its biological underpinnings. New studies have elucidated the contributions of a variety of forms of genetic variation to autism susceptibility. While the roles of de novo copy number variants and single-nucleotide variants-causing loss-of-function or missense changes-have been increasingly recognized and refined, mosaic single-nucleotide variants have been implicated more recently in some cases. Moreover, inherited variants (including common variants) and, more recently, rare recessive inherited variants have come into greater focus. Finally, noncoding variants-both inherited and de novo-have been implicated in the last few years. This work has revealed a convergence of diverse genetic drivers on common biological pathways and has highlighted the ongoing importance of increasing sample size and experimental innovation. Continuing to synthesize these genetic findings with functional and phenotypic evidence and translating these discoveries to clinical care remain considerable challenges for the field.

Transtorno do espectro autista e a suplementação por ácido fólico antes e durante a gestação

RESUMO Objetivo Elucidar se a suplementação com ácido fólico pouco antes da concepção e/ou durante a gestação pode estar realmente atrelado ao desenvolvimento do transtorno do espectro autista (TEA). Metódos Foi realizada uma revisão de literatura em base de dados, nos idiomas português e inglês, durante o período de novembro de 2017 até abril de 2018, com ênfase nas publicações mais recentes. Resultados Do total de 174 artigos, 87 compuseram este trabalho. Pesquisas apontam que o aumento dos casos de TEA se deve ao fato de que mais fatores genéticos estejam implicados na etiopatogênese neural. No entanto, a grande maioria dos artigos ressalta com maior precisão que há mais efeitos benéficos do uso de ácido fólico antes da concepção e durante a gestação na prevenção do TEA, assim como de outras anormalidades relacionadas aos defeitos do tubo neural. Conclusão Quando se analisa o risco-benefício da suplementação com ácido fólico nas doses recomendadas, 0,4 a 0,8 mg/dia, conclui-se que os benefícios sobrepujam os possíveis riscos de desenvolver o TEA.

Needs assessment in genetic testing education: A survey of parents of children with autism spectrum disorder in the united states

Understanding parents' educational needs concerning genetic testing for their children with autism spectrum disorder (ASD) is important in developing tailored, evidence-based health education materials for clinical use. Since research is lacking in this area, to bridge the gap, we examined genetic testing education needs using a nationwide sample of parents of biological children with ASD in the United States. Prospective participants were recruited from the interactive autism network, and 552 parents of biological children with ASD completed the online survey. Most participants (73.7%) were interested in receiving health education about genetic testing. Yet, the majority of them (64.7%) reported that they did not receive the information needed from physicians. Parents who identified as racial/ethnic minorities (P = 0.029), who had an education degree below college (P = 0.002), or displayed low/no awareness of genetic testing (P = 0.003) were more interested in receiving health education regarding genetic testing. Parents' most desired topics for health education include the accuracy of genetic testing (88.4%), cost (85.9%), relevant benefits of such testing (83.8%), testing procedure (77.8%), eligibility to undergo genetic testing for their children with ASD (62.4%), potential harms caused by genetic testing (56.1%), previous use and experience among individuals affected by ASD (50.8%), and confidentiality issues (48.0%). Furthermore, web-based education was the preferable approach (85.4%). Our findings can help develop health education programs and/or materials regarding genetic testing for parents and physicians to facilitate better physician-parent communication and assist parents in making informed medical decisions regarding genetic testing. Autism Res 2019, 12: 1162-1170. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study examined educational needs on genetic testing among 552 American parents of children with autism spectrum disorder (ASD). Results showed that most parents expressed interests in receiving health education regarding genetic testing (73.7%) and favored online education resources (85.4%). Preferred topics included accuracy, cost, and testing benefits. Our findings can help develop genetic testing related health education programs and materials for parents of children with ASD.

Targeted resequencing of 358 candidate genes for autism spectrum disorder in a Chinese cohort reveals diagnostic potential and genotype-phenotype correlations

Autism spectrum disorder (ASD) is a childhood neuropsychiatric disorder with a complex genetic architecture. The diagnostic potential of a targeted panel of ASD genes has only been evaluated in small cohorts to date and is especially understudied in the Chinese population. Here, we designed a capture panel with 358 genes (111 syndromic and 247 nonsyndromic) for ASD and sequenced a Chinese cohort of 539 cases evaluated with the Autism Diagnostic Interview‐Revised (ADI‐R) and the Autism Diagnostic Observation Schedule (ADOS) as well as 512 controls. ASD cases were found to carry significantly more ultra‐rare functional variants than controls. A subset of 78 syndromic and 54 nonsyndromic genes was the most significantly associated and should be given high priority in the future screening of ASD patients. Pathogenic and likely pathogenic variants were detected in 9.5% of cases. Variants in SHANK3 and SHANK2 were the most frequent, especially in females, and occurred in 1.2% of cases. Duplications of 15q11–13 were detected in 0.8% of cases. Variants in CNTNAP2 and MEF2C were correlated with epilepsy/tics in cases. Our findings reveal the diagnostic potential of ASD genetic panel testing and new insights regarding the variant spectrum. Genotype–phenotype correlations may facilitate the diagnosis and management of ASD.

Parental Perception and Participation in Genetic Testing Among Children With Autism Spectrum Disorders

The purpose of this study was to determine the factors associated with genetic testing in children with autism spectrum disorders (ASDs) and understand parental involvement in the decision to test using survey data of parents of children with ASD. Evaluation by a geneticist was associated with genetic testing by more than 39 times compared to evaluation by a nongeneticist (95% CI = 9.15-168.81). Those offered testing by the physicians were more than 6 times more likely to be tested than those not offered testing (95% CI = 1.66-24.61). Financial concerns, not being offered testing, and lack of awareness were the most consistent reasons for not testing given by participants. A physician's recommendation for testing and an evaluation by a geneticist were the most important factors associated with genetic testing in children with ASD. Educating primary care physicians and nongenetic specialists can potentially improve genetic testing among children with ASD.

Clinical and Molecular Characteristics of Mitochondrial Dysfunction in Autism Spectrum Disorder

Autism spectrum disorder (ASD) affects ~ 2% of children in the United States. The etiology of ASD likely involves environmental factors triggering physiological abnormalities in genetically sensitive individuals. One of these major physiological abnormalities is mitochondrial dysfunction, which may affect a significant subset of children with ASD. Here we systematically review the literature on human studies of mitochondrial dysfunction related to ASD. Clinical aspects of mitochondrial dysfunction in ASD include unusual neurodevelopmental regression, especially if triggered by an inflammatory event, gastrointestinal symptoms, seizures, motor delays, fatigue and lethargy. Traditional biomarkers of mitochondrial disease are widely reported to be abnormal in ASD, but appear non-specific. Newer biomarkers include buccal cell enzymology, biomarkers of fatty acid metabolism, non-mitochondrial enzyme function, apoptosis markers and mitochondrial antibodies. Many genetic abnormalities are associated with mitochondrial dysfunction in ASD, including chromosomal abnormalities, mitochondrial DNA mutations and large-scale deletions, and mutations in both mitochondrial and non-mitochondrial nuclear genes. Mitochondrial dysfunction has been described in immune and buccal cells, fibroblasts, muscle and gastrointestinal tissue and the brains of individuals with ASD. Several environmental factors, including toxicants, microbiome metabolites and an oxidized microenvironment are shown to modulate mitochondrial function in ASD tissues. Investigations of treatments for mitochondrial dysfunction in ASD are promising but preliminary. The etiology of mitochondrial dysfunction and how to define it in ASD is currently unclear. However, preliminary evidence suggests that the mitochondria may be a fruitful target for treatment and prevention of ASD. Further research is needed to better understand the role of mitochondrial dysfunction in the pathophysiology of ASD.

Information needs in genetic testing: A needs assessment survey among Taiwanese parents of children with autism spectrum disorders

We conducted the first needs assessment study by examining the information needs in genetic testing for autism spectrum disorders among parents of children with autism spectrum disorders in Taiwan. Parents of children with autism spectrum disorders in 236 public elementary schools with special education services were invited to complete a survey. About two-thirds of participants (65.7%) had never heard about genetic testing for autism spectrum disorders. Yet, the majority (71.4%) expressed an interest in learning about this testing. The top three topics participants identified to assist them in making informed decisions before undergoing genetic testing (for themselves, their affected children, or other family members) were testing accuracy (79.7%), genetic causes of autism spectrum disorders (79.4%), and the link between testing and treatment (79.4%). A health education brochure (47.2%) was the most desired educational approach. Our results can be utilized to develop information and counseling materials for genetic testing for autism spectrum disorders in Taiwan as well as to address the needs of parents of children with autism spectrum disorders, particularly in informed decisions-making. Moreover, to promote better communication between the providers and parents, when discussing genetic testing for autism spectrum disorders with Taiwanese parents of children with autism spectrum disorders, healthcare professionals' priorities should be in line with the preferred topics identified in this study.

Investigation of epigenetic regulatory networks associated with autism spectrum disorder (ASD) by integrated global LINE-1 methylation and gene expression profiling analyses

BACKGROUND

The exact cause and mechanisms underlying the pathobiology of autism spectrum disorder (ASD) remain unclear. Dysregulation of long interspersed element-1 (LINE-1) has been reported in the brains of ASD-like mutant mice and ASD brain tissues. However, the role and methylation of LINE-1 in individuals with ASD remain unclear. In this study, we aimed to investigate whether LINE-1 insertion is associated with differentially expressed genes (DEGs) and to assess LINE-1 methylation in ASD.

METHODS

To identify DEGs associated with LINE-1 in ASD, we reanalyzed previously published transcriptome profiles and overlapped them with the list of LINE-1-containing genes from the TranspoGene database. An Ingenuity Pathway Analysis (IPA) of DEGs associated with LINE-1 insertion was conducted. DNA methylation of LINE-1 was assessed via combined bisulfite restriction analysis (COBRA) of lymphoblastoid cell lines from ASD individuals and unaffected individuals, and the methylation levels were correlated with the expression levels of LINE-1 and two LINE-1-inserted DEGs, C1orf27 and ARMC8.

RESULTS

We found that LINE-1 insertion was significantly associated with DEGs in ASD. The IPA showed that LINE-1-inserted DEGs were associated with ASD-related mechanisms, including sex hormone receptor signaling and axon guidance signaling. Moreover, we observed that the LINE-1 methylation level was significantly reduced in lymphoblastoid cell lines from ASD individuals with severe language impairment and was inversely correlated with the transcript level. The methylation level of LINE-1 was also correlated with the expression of the LINE-1-inserted DEG C1orf27 but not ARMC8.

CONCLUSIONS

In ASD individuals with severe language impairment, LINE-1 methylation was reduced and correlated with the expression levels of LINE-1 and the LINE-1-inserted DEG C1orf27. Our findings highlight the association of LINE-1 with DEGs in ASD blood samples and warrant further investigation. The molecular mechanisms of LINE-1 and the effects of its methylation in ASD pathobiology deserve further study.

Integrated genome-wide Alu methylation and transcriptome profiling analyses reveal novel epigenetic regulatory networks associated with autism spectrum disorder

Background

Alu elements are a group of repetitive elements that can influence gene expression through CpG residues and transcription factor binding. Altered gene expression and methylation profiles have been reported in various tissues and cell lines from individuals with autism spectrum disorder (ASD). However, the role of Alu elements in ASD remains unclear. We thus investigated whether Alu elements are associated with altered gene expression profiles in ASD.

Methods

We obtained five blood-based gene expression profiles from the Gene Expression Omnibus database and human Alu-inserted gene lists from the TranspoGene database. Differentially expressed genes (DEGs) in ASD were identified from each study and overlapped with the human Alu-inserted genes. The biological functions and networks of Alu-inserted DEGs were then predicted by Ingenuity Pathway Analysis (IPA). A combined bisulfite restriction analysis of lymphoblastoid cell lines (LCLs) derived from 36 ASD and 20 sex- and age-matched unaffected individuals was performed to assess the global DNA methylation levels within Alu elements, and the Alu expression levels were determined by quantitative RT-PCR.

Results

In ASD blood or blood-derived cells, 320 Alu-inserted genes were reproducibly differentially expressed. Biological function and pathway analysis showed that these genes were significantly associated with neurodevelopmental disorders and neurological functions involved in ASD etiology. Interestingly, estrogen receptor and androgen signaling pathways implicated in the sex bias of ASD, as well as IL-6 signaling and neuroinflammation signaling pathways, were also highlighted. Alu methylation was not significantly different between the ASD and sex- and age-matched control groups. However, significantly altered Alu methylation patterns were observed in ASD cases sub-grouped based on Autism Diagnostic Interview-Revised scores compared with matched controls. Quantitative RT-PCR analysis of Alu expression also showed significant differences between ASD subgroups. Interestingly, Alu expression was correlated with methylation status in one phenotypic ASD subgroup.

Conclusion

Alu methylation and expression were altered in LCLs from ASD subgroups. Our findings highlight the association of Alu elements with gene dysregulation in ASD blood samples and warrant further investigation. Moreover, the classification of ASD individuals into subgroups based on phenotypes may be beneficial and could provide insights into the still unknown etiology and the underlying mechanisms of ASD.

Electronic supplementary material

The online version of this article (10.1186/s13229-018-0213-9) contains supplementary material, which is available to authorized users.

Mitochondrial dysfunction and autism: comprehensive genetic analyses of children with autism and mtDNA deletion

Background

The etiology of autism spectrum disorders (ASD) is very heterogeneous. Mitochondrial dysfunction has been described in ASD; however, primary mitochondrial disease has been genetically proven in a small subset of patients. The main goal of the present study was to investigate correlations between mitochondrial DNA (mtDNA) changes and alterations of genes associated with mtDNA maintenance or ASD.

Methods

Sixty patients with ASD and sixty healthy individuals were screened for common mtDNA mutations. Next generation sequencing was performed on patients with major mtDNA deletions (mtdel-ASD) using two gene panels to investigate nuclear genes that are associated with ASD or are responsible for mtDNA maintenance. Cohorts of healthy controls, ASD patients without mtDNA alterations, and patients with mitochondrial disorders (non-ASD) harbouring mtDNA deletions served as comparison groups.

Results

MtDNA deletions were confirmed in 16.6% (10/60) of patients with ASD (mtdel-ASD). In 90% of this mtdel-ASD children we found rare SNVs in ASD-associated genes (one of those was pathogenic). In the intergenomic panel of this cohort one likely pathogenic variant was present. In patients with mitochondrial disease in genes responsible for mtDNA maintenance pathogenic mutations and variants of uncertain significance (VUS) were detected more frequently than those found in patients from the mtdel-ASD or other comparison groups. In healthy controls and in patients without a mtDNA deletion, only VUS were detected in both panel.

Conclusions

MtDNA alterations are more common in patients with ASD than in control individuals. MtDNA deletions are not isolated genetic alterations found in ASD; they coexist either with other ASD-associated genetic risk factors or with alterations in genes responsible for intergenomic communication. These findings indicate that mitochondrial dysfunction is not rare in ASD. The occurring mtDNA deletions in ASD may be mostly a consequence of the alterations of the causative culprit genes for autism or genes responsible for mtDNA maintenance, or because of the harmful effect of environmental factors.

Electronic supplementary material

The online version of this article (10.1186/s12993-018-0135-x) contains supplementary material, which is available to authorized users.

Epilepsy in fragile-X-syndrome mimicking panayiotopoulos syndrome: Description of three patients

Fragile-X-syndrome is the most common cause of inherited intellectual disability. Epilepsy is reported to occur in 10-20% of individuals with Fragile-X-syndrome. A frequent seizure/electroencephalogram (EEG) pattern resembles that of benign rolandic epilepsy. We describe the clinical features, EEG findings and evolution in three patients affected by Fragile-X-syndrome and epilepsy mimicking Panayiotopoulos syndrome. Age at seizure onset was between 4 and about 7 years. Seizures pattern comprised a constellation of autonomic symptoms with unilateral deviation of the eyes and ictal syncope. Duration of the seizures could be brief or lengthy. Interictal EEGs revealed functional multifocal abnormalities. The evolution was benign in all patients with seizures remission before the age of 14. This observation expands the spectrum of benign epileptic phenotypes present in Fragile-X-syndrome and may be quite helpful in guiding anticonvulsant management and counseling families as to expectations regarding seizure remission.

Platelets as a surrogate disease model of neurodevelopmental disorders: Insights from Fragile X Syndrome

Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability and the leading monogenic cause of autism spectrum disorders (ASD). Despite a large number of therapeutics developed in past years, there is currently no targeted treatment approved for FXS. In fact, translation of the positive and very promising preclinical findings from animal models to human subjects has so far fallen short owing in part to the low predictive validity of the Fmr1 ko mouse, an overly simplistic model of the complex human disease. This issue stresses the critical need to identify new surrogate human peripheral cell models of FXS, which may in fact allow for the identification of novel and more efficient therapies. Of all described models, blood platelets appear to be one of the most promising and appropriate disease models of FXS, in part owing to their close biochemical similarities with neurons. Noteworthy, they also recapitulate some of FXS neuron's core molecular dysregulations, such as hyperactivity of the MAPK/ERK and PI3K/Akt/mTOR pathways, elevated enzymatic activity of MMP9 and decreased production of cAMP. Platelets might therefore help furthering our understanding of FXS pathophysiology and might also lead to the identification of disease-specific biomarkers, as was shown in several psychiatric disorders such as schizophrenia and Alzheimer's disease. Moreover, there is additional evidence suggesting that platelet signaling may assist with prediction of cognitive phenotype and could represent a potent readout of drug efficacy in clinical trials. Globally, given the neurobiological overlap between different forms of intellectual disability, platelets may be a valuable window to access the molecular underpinnings of ASD and other neurodevelopmental disorders (NDD) sharing similar synaptic plasticity defects with FXS. Platelets are indeed an attractive model for unraveling pathophysiological mechanisms involved in NDD as well as to search for diagnostic and therapeutic biomarkers.

Lessons learned from studying syndromic autism spectrum disorders

Syndromic autism spectrum disorders represent a group of childhood neurological conditions, typically associated with chromosomal abnormalities or mutations in a single gene. The discovery of their genetic causes has increased our understanding of the molecular pathways critical for normal cognitive and social development. Human studies have revealed that the brain is particularly sensitive to changes in dosage of various proteins from transcriptional and translational regulators to synaptic proteins. Investigations of these disorders in animals have shed light on previously unknown pathogenic mechanisms leading to the identification of potential targets for therapeutic intervention. The demonstration of reversibility of several phenotypes in adult mice is encouraging, and brings hope that with novel therapies, skills and functionality might improve in affected children and young adults. As new research reveals points of convergence between syndromic and nonsyndromic autism spectrum disorders, we believe there will be opportunities for shared therapeutics for this class of conditions.

FORWARD: A Registry and Longitudinal Clinical Database to Study Fragile X Syndrome

BACKGROUND AND OBJECTIVE

Advances in the care of patients with fragile X syndrome (FXS) have been hampered by lack of data. This deficiency has produced fragmentary knowledge regarding the natural history of this condition, healthcare needs, and the effects of the disease on caregivers. To remedy this deficiency, the Fragile X Clinic and Research Consortium was established to facilitate research. Through a collective effort, the Fragile X Clinic and Research Consortium developed the Fragile X Online Registry With Accessible Research Database (FORWARD) to facilitate multisite data collection. This report describes FORWARD and the way it can be used to improve health and quality of life of FXS patients and their relatives and caregivers.

METHODS

FORWARD collects demographic information on individuals with FXS and their family members (affected and unaffected) through a 1-time registry form. The longitudinal database collects clinician- and parent-reported data on individuals diagnosed with FXS, focused on those who are 0 to 24 years of age, although individuals of any age can participate.

RESULTS

The registry includes >2300 registrants (data collected September 7, 2009 to August 31, 2014). The longitudinal database includes data on 713 individuals diagnosed with FXS (data collected September 7, 2012 to August 31, 2014). Longitudinal data continue to be collected on enrolled patients along with baseline data on new patients.

CONCLUSIONS

FORWARD represents the largest resource of clinical and demographic data for the FXS population in the United States. These data can be used to advance our understanding of FXS: the impact of cooccurring conditions, the impact on the day-to-day lives of individuals living with FXS and their families, and short-term and long-term outcomes.

Examining the Overlap between Autism Spectrum Disorder and 22q11.2 Deletion Syndrome

22q11.2 deletion syndrome (22q11.2DS) is a genomic disorder reported to associate with autism spectrum disorders (ASDs) in 15–50% of cases; however, others suggest that individuals with 22q11.2DS present psychiatric or behavioral features associated with ASDs, but do not meet full criteria for ASD diagnoses. Such wide variability in findings may arise in part due to methodological differences across studies. Our study sought to determine whether individuals with 22q11.2DS meet strict ASD diagnostic criteria using research-based guidelines from the Collaborative Programs of Excellence in Autism (CPEA), which required a gathering of information from three sources: the Autism Diagnostic Interview-Revised (ADI-R), the Autism Diagnostic Observational Schedule (ADOS), and a clinician’s best-estimate diagnosis. Our study examined a cohort of children, adolescents, and young adults (n = 56) with 22q11.2DS, who were ascertained irrespective of parents’ behavioral or developmental concerns, and found that 17.9% (n = 10) of the participants met CPEA criteria for an ASD diagnosis, and that a majority showed some level of social-communication impairment or the presence of repetitive behaviors. We conclude that strictly defined ASDs occur in a substantial proportion of individuals with 22q11.2DS, and recommend that all individuals with 22q11.2DS be screened for ASDs during early childhood.

Fetal origins of autism spectrum disorders: the non-associated maternal factors

Aim:

Several population-based studies have been conducted to determine whether maternal exposures are involved in the pathophysiology of autism spectrum disorder (ASD). We review these studies and describe the factors not associated with increased risk for ASD development.

Methods:

We identified studies describing associations between maternal exposures and ASD development. These studies include the Childhood Autism Risks from Genetics and the Environment, Nurses’ Health Study II, and the Swedish population registry.

Results:

Factors not associated with ASD development include Type 2 and gestational diabetes, chronic hypertension, fever treated with antipyretic medication, autoimmune disease and short interpregnancy intervals.

Conclusion:

There is increasing evidence that maternal exposures are involved in the pathophysiology of ASD in the developing fetus.

Lay Abstract: Autism spectrum disorder currently affects one in 68 children in the USA, with up to one in 42 boys. Its underlying etiology is largely unknown. Although autism was once considered a childhood disease, efforts for early detection led to the realization that it might originate at a much earlier stage, namely fetal life. Several maternal risk factors have recently been studied to establish associations with autism in the offspring. In this review, we present the maternal risk factors that were not found to have such associations.

Copy Number Variants in Patients with Autism and Additional Clinical Features: Report of VIPR2 Duplication and a Novel Microduplication Syndrome

Autism is a common neurodevelopmental disorder estimated to affect 1 in 68 children. Many studies have shown the role of copy number variants (CNVs) as a major contributor in the etiology of autism with the overall detection rate of about 10-15 % and over 20 % when syndromic forms of autism exist. In this study, we used array CGH to identify CNVs in 15 Iranian patients with autism. To elevate our diagnostic yield, we selected the sporadic patients who had additional clinical features including intellectual disability (ID), craniofacial anomaly, and seizure. Six out of 15 patients showed clinically relevant CNVs including pathogenic and likely pathogenic copy number gains or losses. We report a novel gene duplication syndrome (10q21.2q21.3 microduplication) and present a new evidence for VIPR2 duplication, as a candidate gene for autism. Furthermore, we describe the first manifesting carrier female with deletion of SLC6A8 and BCAP31 genes on Xq28. Our findings suggest that there might be a higher prevalence of clinically significant CNVs in patients with autism and additional clinical manifestations. The CNV analysis in such patients could lead to the discovery of novel syndromes as well as unraveling the etiology of autism.

Clinicians' experiences with the fragile X clinical and research consortium

The objectives of the study were to assess the attitudes and experiences of clinicians involved in a consortium of clinics serving people with fragile X-associated disorders to gauge satisfaction with the consortium and its efforts to improve quality of life for patients and the community. An internet survey was sent to 26 fragile X (FX) clinic directors participating in the Fragile X Clinical and Research Consortium (FXCRC). Respondents were asked to complete 19 questions on consortium performance and outcomes relevant for their own clinic. The response rate was 84% (22/26), with two surveys providing incomplete data. Assistance with clinic establishment, opportunities for research collaborations, and access to colleagues and information were highly valued. Approximately 76% of clinicians reported improvements in patient care and 60% reported an increase in patient services. There was a 57% increase in participation in a FX-related clinical trial among clinics since joining the FXCRC (24% vs. 81%). Overall, respondents reported primarily positive experiences from participation in the FXCRC. Common suggestions for improvement included additional financial support and increased utilization of collected patient data for research purposes. Additionally, a Clinic Services Checklist was administered annually to examine changes in services offered over time. There were several important changes regarding the provision of services by clinics, often with multiple clinics changing with respect to a service. In conclusion, the FXCRC has led to the establishment and sustainment of fragile X clinics in the U.S., fostered cooperation among fragile X clinicians, and provided clinics with a platform to share recommendations and best practices to maximize quality of life for their patients and the overall fragile X community. The results from the survey and checklist also provide suggestions to strengthen the FXCRC and enhance future collaborations among FXCRC members. © 2016 Wiley Periodicals, Inc.

Fragile X syndrome: A review of clinical management

The fragile X mental retardation 1 gene, which codes for the fragile X mental retardation 1 protein, usually has 5 to 40 CGG repeats in the 5' untranslated promoter. The full mutation is the almost always the cause of fragile X syndrome (FXS). The prevalence of FXS is about 1 in 4,000 to 1 in 7,000 in the general population although the prevalence varies in different regions of the world. FXS is the most common inherited cause of intellectual disability and autism. The understanding of the neurobiology of FXS has led to many targeted treatments, but none have cured this disorder. The treatment of the medical problems and associated behaviors remain the most useful intervention for children with FXS. In this review, we focus on the non-pharmacological and pharmacological management of medical and behavioral problems associated with FXS as well as current recommendations for follow-up and surveillance.

Behavioral Phenotype of Fmr1 Knock-Out Mice during Active Phase in an Altered Light/Dark Cycle

Fragile X syndrome (FXS) is the most commonly inherited form of intellectual disability and is a disorder that is also highly associated with autism. FXS occurs as a result of an expanded CGG repeat sequence leading to transcriptional silencing. In an animal model of FXS in which Fmr1 is knocked out (Fmr1 KO), many physical, physiological, and behavioral characteristics of the human disease are recapitulated. Prior characterization of the mouse model was conducted during the day, the inactive phase of the circadian cycle. Circadian rhythms are an important contributor to behavior and may play a role in the study of disease phenotype. Moreover, changes in the parameters of circadian rhythm are known to occur in FXS animal models. We conducted an investigation of key behavioral phenotypes in Fmr1 KO mice during their active phase. We report that phase did not alter the Fmr1 KO phenotype in open field activity, anxiety, and learning and memory. There was a slight effect of phase on social behavior as measured by time in chamber, but not by time spent sniffing. Our data strengthen the existing data characterizing the phenotype of Fmr1 KO mice, indicating that it is independent of circadian phase.

Autism spectrum disorders: Integration of the genome, transcriptome and the environment

Autism spectrum disorders denote a series of lifelong neurodevelopmental conditions characterized by an impaired social communication profile and often repetitive, stereotyped behavior. Recent years have seen the complex genetic architecture of the disease being progressively unraveled with advancements in gene finding technology and next generation sequencing methods. However, a complete elucidation of the molecular mechanisms behind autism is necessary for potential diagnostic and therapeutic applications. A multidisciplinary approach should be adopted where the focus is not only on the 'genetics' of autism but also on the combinational roles of epigenetics, transcriptomics, immune system disruption and environmental factors that could all influence the etiopathogenesis of the disease. ASD is a clinically heterogeneous disorder with great genetic complexity; only through an integrated multidimensional effort can modern autism research progress further.

Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit

Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were 'odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology.

Clinical Genetic Aspects of ASD Spectrum Disorders

Early presumptions opined that autism spectrum disorder (ASD) was related to the rearing of these children by emotionally-distant mothers. Advances in the 1960s and 1970s clearly demonstrated the biologic basis of autism with a high heritability. Recent advances have demonstrated that specific etiologic factors in autism spectrum disorders can be identified in 30%–40% of cases. Based on early reports newer, emerging genomic technologies are likely to increase this diagnostic yield to over 50%. To date these investigations have focused on etiologic factors that are largely mono-factorial. The currently undiagnosed causes of ASDs will likely be found to have causes that are more complex. Epigenetic, multiple interacting loci, and four dimensional causes (with timing as a variable) are likely to be associated with the currently unidentifiable cases. Today, the “Why” is more important than ever. Understanding the causes of ASDs help inform families of important issues such as recurrence risk, prognosis, natural history, and predicting associated co-morbid medical conditions. In the current era of emerging efforts in “personalized medicine”, identifying an etiology will be critical in identifying endo-phenotypic groups and individual variations that will allow for tailored treatment for persons with ASD.

Autism Spectrum Disorder - A Complex Genetic Disorder

Autism spectrum disorder is an entity that reflects a scientific consensus that several previously separated disorders are actually a single spectrum disorder with different levels of symptom severity in two core domains - deficits in social communication and interaction, and restricted repetitive behaviors. Autism spectrum disorder is diagnosed in all racial, ethnic and socioeconomic groups and because of its increased prevalence, reported worldwide through the last years, made it one of the most discussed child psychiatric disorders. In term of aetiology as several other complex diseases, Autism spectrum disorder is considered to have a strong genetic component.

Genetics in child and adolescent psychiatry: methodological advances and conceptual issues

Discovering the genetic basis of early-onset psychiatric disorders has been the aim of intensive research during the last decade. We will first selectively summarize results of genetic research in child and adolescent psychiatry by using examples from different disorders and discuss methodological issues, emerging questions and future directions. In the second part of this review, we will focus on how to link genetic causes of disorders with physiological pathways, discuss the impact of genetic findings on diagnostic systems, prevention and therapeutic interventions. Finally we will highlight some ethical aspects connected to genetic research in child and adolescent psychiatry. Advances in molecular genetic methods have led to insights into the genetic architecture of psychiatric disorders, but not yet provided definite pathways to pathophysiology. If replicated, promising findings from genetic studies might in some cases lead to personalized treatments. On the one hand, knowledge of the genetic basis of disorders may influence diagnostic categories. On the other hand, models also suggest studying the genetic architecture of psychiatric disorders across diagnoses and clinical groups.