Longitudinal stability of salivary microRNA biomarkers in children and adolescents with autism spectrum disorder.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurological condition with increasing prevalence. Few tools accurately predict the developmental trajectory of children with ASD. Such tools would allow clinicians to provide accurate prognoses and track the efficacy of therapeutic interventions. Salivary RNAs that reflect the genetic-environmental interactions underlying ASD may provide objective measures of symptom severity and developmental outcomes. This study investigated whether salivary RNAs previously identified in childhood ASD remain perturbed in older children. We also explored whether RNA candidates changed with therapeutic intervention. METHOD: A case-control design was used to characterize levels of 78 saliva RNA candidates among 96 children (48 ASD, 48 non-ASD, mean age: 11 years). Thirty-one children (22 ASD, 9 non-ASD developmental delay, mean age: 4 years) were followed longitudinally to explore changes of RNA candidates during early intervention. Saliva RNA and standardized behavioral assessments were collected for each participant. Associations between candidate RNAs and behavioral scores were determined in both groups via Spearman Correlation. Changes in candidate RNAs across two time-points were assessed in the younger cohort via Wilcoxon rank-sum test. RESULTS: Seven RNAs were associated with VABS-II and BASC scores in the older group ([R] >0.25, FDR< 0.15). Within the younger cohort, 12 RNAs displayed significant changes over time (FDR< 0.05). Three microRNAs were associated with behavioral scores and changed over time (miR-182-5p, miR-146b-5p, miR-374a-5p). CONCLUSION: Several salivary RNAs are strongly associated with autistic behaviors in older individuals with ASD and change as early as three months after therapy initiation in younger children. These molecules could be used to track treatment effectiveness and provide prognoses. Further validation is necessary.

Evidence-based use of scalable biomarkers to increase diagnostic efficiency and decrease the lifetime costs of autism.

Challenges associated with the current screening and diagnostic process for autism spectrum disorder (ASD) in the US cause a significant delay in the initiation of evidence-based interventions at an early age when treatments are most effective. The present study shows how implementing a second-order diagnostic measure to high risk cases initially flagged positive from screening tools can further inform clinical judgment and substantially improve early identification. We use two example measures for the purposes of this demonstration; a saliva test and eye-tracking technology, both scalable and easy-to-implement biomarkers recently introduced in ASD research. Results of the current cost-savings analysis indicate that lifetime societal cost savings in special education, medical and residential care are estimated to be nearly $580,000 per ASD child, with annual cost savings in education exceeding $13.3 billion, and annual cost savings in medical and residential care exceeding $23.8 billion (of these, nearly $11.2 billion are attributable to Medicaid). These savings total more than $37 billion/year in societal savings in the US. Initiating appropriate interventions faster and reducing the number of unnecessary diagnostic evaluations can decrease the lifetime costs of ASD to society. We demonstrate the value of implementing a scalable highly accurate diagnostic in terms of cost savings to the US. LAY SUMMARY: This paper demonstrates how biomarkers with high accuracy for detecting autism spectrum disorder (ASD) could be used to increase the efficiency of early diagnosis. Results also show that, if more children with ASD are identified early and referred for early intervention services, the system would realize substantial costs savings across the lifespan.

Initial Responsiveness to Reward Attainment and Psychopathology in Children and Adults: An RDoC Study.

The Research Domain Criteria (RDoC) initiative of the National Institute of Mental Health (NIMH) established a dimensional framework for understanding psychiatric constructs. Initial Responsiveness to Reward Attainment (IRRA) was identified as a dimensional construct relevant to several psychiatric disorders. The current study aimed to (1) examine IRRA as a predictor of psychopathology and impairment in children and their parents, and (2) examine the potential effects of sex and ancestry on the relationship between IRRA and psychopathology. Participants included 1127 children ages 6 to 12, and 1018 of their parents. Parents and children completed self-report measures of IRRA. Psychopathology and impairment were measured using self-report for adults, and parent-report and semi-structured interview for children. In adults, IRRA was significantly, but modestly, related to adaptive functioning. In children, IRRA was significantly, but modestly, related to overall, school, spare time, home, and peer functioning. Findings suggest IRRA may be a helpful construct for understanding adaptive functioning in adults and children, however it may be less helpful for understanding specific dimensions of psychopathology. Additionally, ancestry should be taken into consideration when examining how IRRA relates to psychopathology and functioning.

Saliva MicroRNA Differentiates Children With Autism From Peers With Typical and Atypical Development.

OBJECTIVE: Clinical diagnosis of autism spectrum disorder (ASD) relies on time-consuming subjective assessments. The primary purpose of this study was to investigate the utility of salivary microRNAs for differentiating children with ASD from peers with typical development (TD) and non-autism developmental delay (DD). The secondary purpose was to explore microRNA patterns among ASD phenotypes. METHOD: This multicenter, prospective, case-control study enrolled 443 children (2-6 years old). ASD diagnoses were based on DSM-5 criteria. Children with ASD or DD were assessed with the Autism Diagnostic Observation Schedule II and Vineland Adaptive Behavior Scales II. MicroRNAs were measured with high-throughput sequencing. Differential expression of microRNAs was compared among the ASD (n = 187), TD (n = 125), and DD (n = 69) groups in the training set (n = 381). Multivariate logistic regression defined a panel of microRNAs that differentiated children with ASD and those without ASD. The algorithm was tested in a prospectively collected naïve set of 62 samples (ASD, n = 37; TD, n = 8; DD, n = 17). Relations between microRNA levels and ASD phenotypes were explored. RESULT: Fourteen microRNAs displayed differential expression (false discovery rate < 0.05) among ASD, TD, and DD groups. A panel of 4 microRNAs (controlling for medical/demographic covariates) best differentiated children with ASD from children without ASD in training (area under the curve = 0.725) and validation (area under the curve = 0.694) sets. Eight microRNAs were associated (R > 0.25, false discovery rate < 0.05) with social affect, and 10 microRNAs were associated with restricted/repetitive behavior. CONCLUSION: Salivary microRNAs are "altered" in children with ASD and associated with levels of ASD behaviors. Salivary microRNA collection is noninvasive, identifying ASD-status with moderate accuracy. A multi-"omic" approach using additional RNA families could improve accuracy, leading to clinical application. CLINICAL TRIAL REGISTRATION INFORMATION: A Salivary miRNA Diagnostic Test for Autism; https://clinicaltrials.gov/; NCT02832557.

Parent Perspectives Towards Genetic and Epigenetic Testing for Autism Spectrum Disorder.

Examining community views on genetic/epigenetic research allows collaborative technology development. Parent perspectives toward genetic/epigenetic testing for autism spectrum disorder (ASD) are not well-studied. Parents of children with ASD (n = 131), non-ASD developmental delay (n = 39), and typical development (n = 74) completed surveys assessing genetic/epigenetic knowledge, genetic/epigenetic concerns, motives for research participation, and attitudes/preferences toward ASD testing. Most parents (96%) were interested in saliva-based molecular testing for ASD. Some had concerns about privacy (14%) and insurance-status (10%). None (0%) doubted scientific evidence behind genetic/epigenetic testing. Most reported familiarity with genetics (88%), but few understood differences from epigenetics (19%). Child developmental status impacted insurance concerns (p = 0.01). There is broad parent interest in a genetic/epigenetic test for ASD. It will be crucial to carefully consider and address bioethical issues surrounding this sensitive topic while developing such technology.

Validation of a Salivary RNA Test for Childhood Autism Spectrum Disorder.

Background: The diagnosis of autism spectrum disorder (ASD) relies on behavioral assessment. Efforts to define biomarkers of ASD have not resulted in an objective, reliable test. Studies of RNA levels in ASD have demonstrated potential utility, but have been limited by a focus on single RNA types, small sample sizes, and lack of developmental delay controls. We hypothesized that a saliva-based poly-"omic" RNA panel could objectively distinguish children with ASD from their neurotypical peers and children with non-ASD developmental delay. Methods: This multi-center cross-sectional study included 456 children, ages 19-83 months. Children were either neurotypical (n = 134) or had a diagnosis of ASD (n = 238), or non-ASD developmental delay (n = 84). Comprehensive human and microbial RNA abundance was measured in the saliva of all participants using unbiased next generation sequencing. Prior to analysis, the sample was randomly divided into a training set (82% of subjects) and an independent validation test set (18% of subjects). The training set was used to develop an RNA-based algorithm that distinguished ASD and non-ASD children. The validation set was not used in model development (feature selection or training) but served only to validate empirical accuracy. Results: In the training set (n = 372; mean age 51 months; 75% male; 51% ASD), a set of 32 RNA features (controlled for demographic and medical characteristics), identified ASD status with a cross-validated area under the curve (AUC) of 0.87 (95% CI: 0.86-0.88). In the completely separate validation test set (n = 84; mean age 50 months; 85% male; 60% ASD), the algorithm maintained an AUC of 0.88 (82% sensitivity and 88% specificity). Notably, the RNA features were implicated in physiologic processes related to ASD (axon guidance, neurotrophic signaling). Conclusion: Salivary poly-omic RNA measurement represents a novel, non-invasive approach that can accurately identify children with ASD. This technology could improve the specificity of referrals for ASD evaluation or provide objective support for ASD diagnoses.

Childhood Predictors of Young Adult Social Functioning in 22q11.2 Deletion Syndrome.

The primary objectives of the current prospective longitudinal study were to (a) describe social functioning outcomes and (b) identify childhood predictors of social functioning in young adults with 22q11.2 deletion syndrome (22q11.2DS). Childhood predictors of young adult social functioning were examined. Family environment and parental stress in adolescence were investigated as potential mediators between childhood variables and adult social functioning. Parent rated childhood internalizing symptoms significantly predicted young adult social functioning in 22q11.2DS, even after controlling for concurrent positive symptoms of psychosis, and problem behaviors contributing to parenting stress in adolescence partially mediated this relationship. These findings highlight child internalizing symptoms and adolescent problem behaviors as potential targets for social functioning interventions in 22q11.2DS.

An update on the comorbidity of ADHD and ASD: a focus on clinical management.

Attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) commonly co-occur. With the DSM-5, clinicians are permitted to make an ASD diagnosis in the context of ADHD. In earlier versions of the DSM, this was not acceptable. Both ASD and ADHD are reported to have had substantial increases in prevalence within the past 10 years. As a function of both the increased prevalence of both disorders as well as the ability to make an ASD diagnosis in ADHD, there has been a significant amount of research focusing on the comorbidity between ADHD and ASD in the past few years. Here, we provide an update on the biological, cognitive and behavioral overlap/distinctiveness between the two neurodevelopmental disorders with a focus on data published in the last four years. Treatment strategies for the comorbid condition as well as future areas of research and clinical need are discussed.

The influence of genes on "positive valence systems" constructs: A systematic review.

In 2009, the U.S. National Institute of Mental Health (NIMH) proposed an approach toward the deconstruction of psychiatric nosology under the research domain criteria (RDoC) framework. The overarching goal of RDoC is to identify robust, objective measures of behavior, emotion, cognition, and other domains that are more closely related to neurobiology than are diagnoses. A preliminary framework has been constructed, which has connected molecules, genes, brain circuits, behaviors, and other elements to dimensional psychiatric constructs. Although the RDoC framework has salience in emerging studies, foundational literature that pre-dated this framework requires synthesis and translation to the evolving objectives and nomenclature of RDoC. Toward this end, we review the candidate-gene association, linkage, and genome-wide studies that have implicated a variety of loci and genetic polymorphisms in selected Positive Valence Systems (PVS) constructs. Our goal is to review supporting evidence to currently listed genes implicated in this domain and novel candidates. We systematically searched and reviewed literature based on keywords listed under the June, 2011, edition of the PVS matrix on the RDoC website (http://www.nimh.nih.gov/research-priorities/rdoc/positive-valence-systems-workshop-proceedings.shtml), which were supplemented with de novo keywords pertinent to the scope of our review. Several candidate genes linked to the PVS framework were identified from candidate-gene association studies. We also identified novel candidates with loose association to PVS traits from genome-wide studies. There is strong evidence suggesting that PVS constructs, as currently conceptualized under the RDoC initiative, index genetically influenced traits; however, future research, including genetic epidemiological, and psychometric analyses, must be performed.