Childhood Academic Performance: A Potential Marker of Genetic Liability to Autism.

Autism spectrum disorder (ASD), a heritable neurodevelopmental disorder, confers genetic liability that is often expressed among relatives through subclinical, genetically-meaningful traits, or endophenotypes. For instance, relative to controls, parents of individuals with ASD differ in language-related skills, with differences emerging in childhood. To examine ASD-related endophenotypes, this study investigated developmental academic profiles among clinically unaffected siblings of individuals with ASD (n = 29). Lower performance in language-related skills among siblings mirrored previously-reported patterns among parents, which were also associated with greater subclinical ASD-related traits in themselves and their parents, and with greater symptom severity in their sibling with ASD. Findings demonstrated specific phenotypes, derived from standardized academic testing, that may represent childhood indicators of genetic liability to ASD in first-degree relatives.

Neuropsychological and ASD phenotypes in rare genetic syndromes: A critical review of the literature.

OBJECTIVE: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by core deficits in social communication and restricted and repetitive behaviors and interests. Recent advances in clinical genetics have improved our understanding of genetic syndromes associated with ASD, which has helped clarify distinct etiologies of ASD and document syndrome-specific profiles of neurocognitive strengths and weaknesses. Pediatric neuropsychologists have the potential to be impactful members of the care team for children with genetic syndromes and their families. METHOD: We provide a critical review of the current literature related to the neuropsychological profiles of children with four genetic syndromes associated with ASD, including Tuberous Sclerosis Complex (TSC), fragile X syndrome (FXS), 22q11.2 deletion syndrome, and Angelman syndrome. Recommendations for assessment, intervention, and future directions are provided. RESULTS: There is vast heterogeneity in terms of the cognitive, language, and developmental abilities of these populations. The within- and across-syndrome variability characteristic of genetic syndromes should be carefully considered during clinical evaluations, including possible measurement limitations, presence of intellectual disability, and important qualitative differences in the ASD-phenotypes across groups. CONCLUSIONS: Individuals with genetic disorders pose challenging diagnostic and assessment questions. Pediatric neuropsychologists with expertise in neurodevelopmental processes are well suited to address these questions and identify profiles of neurocognitive strengths and weaknesses, tailor individualized recommendations, and provide diagnostic clarification.

A Longitudinal Study of Parent-Child Interactions and Language Outcomes in Fragile X Syndrome and Other Neurodevelopmental Disorders.

Difficulties with pragmatic language (i.e., language in social contexts, such as conversational ability) are a noted characteristic of the language profiles of both fragile X syndrome (FXS) and autism spectrum disorder (ASD), conditions which show significant phenotypic overlap. Understanding the origins and developmental course of pragmatic language problems in FXS and other developmental conditions associated with language impairment is a critical step for the development of targeted interventions to promote communicative competence across the lifespan. This study examined pragmatic language in the context of parent-child interactions in school-age children with FXS (who did and did not meet ASD criteria on the ADOS; n = 85), idiopathic ASD (n = 32), Down syndrome (DS; n = 38), and typical development (TD; n = 39), and their parents. Parent-child communicative interactions were examined across multiple contexts, across groups, and in relationship to pragmatic language outcomes assessed 2 years later. Results showed both overlapping and divergent patterns across the FXS-ASD and idiopathic ASD child and parent groups, and also highlighted key differences in pragmatic profiles based on situational context, with more pragmatic language difficulties occurring for both ASD groups in less structured interactions. Differences in parental language styles during parent-child interactions were associated with child language outcomes, likely reflecting the complex interplay of discourse style inherent to a parent, with the inevitable influence of child characteristics on parent language as well. Together, findings help delineate the dynamic and multifactorial nature of impaired pragmatic skills among children with FXS and other neurodevelopmental disorders associated with language impairment, with potential implications for the development of targeted interventions for pragmatic communication skills.

The Phenotypic Profile Associated With the FMR1 Premutation in Women: An Investigation of Clinical-Behavioral, Social-Cognitive, and Executive Abilities.

The FMR1 gene in its premutation (PM) state has been linked to a range of clinical and subclinical phenotypes among FMR1 PM carriers, including some subclinical traits associated with autism spectrum disorder (ASD). This study attempted to further characterize the phenotypic profile associated with the FMR1 PM by studying a battery of assessments examining clinical-behavioral traits, social-cognitive, and executive abilities in women carrying the FMR1 PM, and associations with FMR1-related variability. Participants included 152 female FMR1 PM carriers and 75 female controls who were similar in age and IQ, and screened for neuromotor impairments or signs of fragile X-associated tremor/ataxia syndrome. The phenotypic battery included assessments of ASD-related personality and language (i.e., pragmatic) traits, symptoms of anxiety and depression, four different social-cognitive tasks that tapped the ability to read internal states and emotions based on different cues (e.g., facial expressions, biological motion, and complex social scenes), and a measure of executive function. Results revealed a complex phenotypic profile among the PM carrier group, where subtle differences were observed in pragmatic language, executive function, and social-cognitive tasks that involved evaluating basic emotions and trustworthiness. The PM carrier group also showed elevated rates of ASD-related personality traits. In contrast, PM carriers performed similarly to controls on social-cognitive tasks that involved reliance on faces and biological motion. The PM group did not differ from controls on self-reported depression or anxiety symptoms. Using latent profile analysis, we observed three distinct subgroups of PM carriers who varied considerably in their performance across tasks. Among PM carriers, CGG repeat length was a significant predictor of pragmatic language violations. Results suggest a nuanced phenotypic profile characterized by subtle differences in select clinical-behavioral, social-cognitive, and executive abilities associated with the FMR1 PM in women.

Elevated Polygenic Burden for Autism Spectrum Disorder Is Associated With the Broad Autism Phenotype in Mothers of Individuals With Autism Spectrum Disorder.

BACKGROUND: Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental disorder that encompasses a complex and heterogeneous set of traits. Subclinical traits that mirror the core features of ASD, referred to as the broad autism phenotype (BAP), have been documented repeatedly in unaffected relatives and are believed to reflect underlying genetic liability to ASD. The BAP may help inform the etiology of ASD by allowing the stratification of families into more phenotypically and etiologically homogeneous subgroups. This study explores polygenic scores related to the BAP. METHODS: Phenotypic and genotypic information were obtained from 2614 trios from the Simons Simplex Collection. Polygenic scores of ASD (ASD-PGSs) were generated across the sample to determine the shared genetic overlap between the BAP and ASD. Maternal and paternal ASD-PGSs were explored in relation to BAP traits and their child's ASD symptomatology. RESULTS: Maternal pragmatic language was related to child's social communicative atypicalities. In fathers, rigid personality was related to increased repetitive behaviors in children. Maternal (but not paternal) ASD-PGSs were related to the pragmatic language and rigid BAP domains. CONCLUSIONS: Associations emerged between parent and child phenotypes, with more associations emerging in mothers than in fathers. ASD-PGS associations emerged with BAP in mothers only, highlighting the potential for a female protective factor, and implicating the polygenic etiology of ASD-related phenotypes in the BAP.

Epidemiology and Outcomes of Acute Decompensated Heart Failure in Children.

BACKGROUND: Acute decompensated heart failure (ADHF) is a highly morbid condition among adults. Little is known about outcomes in children with ADHF. We analyzed the Pediatric Cardiac Critical Care Consortium registry to determine the epidemiology, contemporary treatments, and predictors of mortality in critically ill children with ADHF. METHODS: Cardiac intensive care unit (CICU) patients ≤18 years of age meeting Pediatric Cardiac Critical Care Consortium criteria for ADHF were included. ADHF was defined as systolic or diastolic dysfunction requiring continuous vasoactive or diuretic infusion, respiratory support, or mechanical circulatory support. Demographics, diagnosis, therapies, complications, and mortality are described for the cohort. Predictors of CICU mortality were identified using logistic regression. RESULTS: Among 26 294 consecutive admissions (23 centers), 1494 (6%) met criteria for analysis. Median age was 0.93 years (interquartile range, 0.1-9.3 years). Patients with congenital heart disease (CHD) comprised 57% of the cohort. Common therapies included the following: vasoactive infusions (88%), central venous catheters (86%), mechanical ventilation (59%), and high flow nasal cannula (46%). Common complications were arrhythmias (19%), cardiac arrest (10%), sepsis (7%), and acute renal failure requiring dialysis (3%). Median length of CICU stay was 7.9 days (interquartile range, 3-18 days) and the CICU readmission rate was 22%. Overall, CICU mortality was 15% although higher for patients with CHD versus non-CHD (19% versus 11%; P<0.001). Independent risk factors associated with CICU mortality included age <30 days, CHD, vasoactive infusions, ventricular tachycardia, mechanical ventilation, sepsis, pulmonary hypertension, extracorporeal membrane oxygenation, and cardiac arrest. CONCLUSIONS: ADHF in children is characterized by comorbidities, high mortality rates, and frequent readmission, especially among patients with CHD. Opportunities exist to determine best practices around appropriate use of mechanical support, cardiac arrest prevention, and optimal heart transplantation candidacy to improve outcomes for these patients.

Intensive Care Unit and Acute Care Unit Length of Stay After Congenital Heart Surgery.

BACKGROUND: Postoperative length of stay (LOS) is an important quality metric and is known to vary widely across hospitals after congenital heart surgery. Whether this variability is explained by factors associated with the intensive care unit (ICU) or acute care unit (ACU) remains unclear. We evaluated the relationship between ICU and ACU LOS and the impact of ACU characteristics on postoperative LOS. METHODS: Hospitalizations for congenital heart surgery within the Pediatric Cardiac Critical Care Consortium (PC4) registry (August 2014 to February 2018) were included. Models were developed for ICU, ACU, and postoperative LOS by adjusting for differences in case-mix across hospitals. PC4 hospitals participating in the Pediatric Acute Care Cardiology Collaborative (PAC3) were also surveyed on ACU organizational factors and practice patterns. RESULTS: Overall, 19,674 hospitalizations across 27 hospitals were included. There was significant variation in ICU and ACU LOS. Postperative LOS appeared to be most closely related to ICU LOS; 75% (6 of 8) of hospitals with shorter than expected postoperative LOS also had shorter than expected ICU LOS. A clear relationship between postoperative and ACU LOS was not observed. Hospitals with an ACU able to provide higher-acuity care as indexed according to the PAC3 survey were more likely to have shorter postoperative LOS (P < .01). CONCLUSIONS: For hospitals that achieve shorter than expected postoperative LOS after congenital heart surgery, ICU LOS appears to be the primary driver. Higher-acuity resources in the ACU may be an important factor facilitating earlier transfer from the ICU. These data are key to informing quality improvement initiatives geared toward reducing postoperative LOS.

Effects of Noise on the Behavioral and Neural Categorization of Speech.

We investigated whether the categorical perception (CP) of speech might also provide a mechanism that aids its perception in noise. We varied signal-to-noise ratio (SNR) [clear, 0 dB, -5 dB] while listeners classified an acoustic-phonetic continuum (/u/ to /a/). Noise-related changes in behavioral categorization were only observed at the lowest SNR. Event-related brain potentials (ERPs) differentiated category vs. category-ambiguous speech by the P2 wave (~180-320 ms). Paralleling behavior, neural responses to speech with clear phonetic status (i.e., continuum endpoints) were robust to noise down to -5 dB SNR, whereas responses to ambiguous tokens declined with decreasing SNR. Results demonstrate that phonetic speech representations are more resistant to degradation than corresponding acoustic representations. Findings suggest the mere process of binning speech sounds into categories provides a robust mechanism to aid figure-ground speech perception by fortifying abstract categories from the acoustic signal and making the speech code more resistant to external interferences.

Analysis of Inflammatory Cytokines in Postoperative Fontan Pleural Drainage.

Prolonged pleural drainage is a common complication in patients after Fontan palliation and is associated with short- and long- term morbidities. Among many potential etiologies, prolonged drainage has an inflammatory component, but there are no descriptions of cytokines in Fontan pleural drainage to date. This study aimed to examine the inflammatory make-up of Fontan pleural drainage. This prospective age-range-matched cohort study recruited 25 patients undergoing Fontan procedure and 15 bi-ventricular patients undergoing cardiopulmonary bypass (CPB). Chest tube samples were taken on postoperative day (POD) 1-4, 7, and 10. Cytokines were measured using Bio-Plex Assays. Univariate comparisons were made in patient characteristics and cytokine levels. Median age was 3.7 y (IQR 2.8-3.9) for controls and 2.5 y (IQR 2.1-2.9) in Fontan patients (p = 0.02). Median drainage duration and daily volume was higher in Fontan patients (both p < 0.001). Inflammatory cytokines (IL-17A, IFN-y, MIP-1ß, and TNF-α) were higher in Fontan patients than controls (all p < 0.02). There was an increase in pro-inflammatory cytokines (IL-8, MIP-1ß, and TNF-α) from POD1 to the last chest tube day (LCD) in Fontan patients (all p < 0.0001) and a decrease in the anti-inflammatory cytokine IL-10 (p = 0.001). There was no difference in cytokine concentration from POD1 to LCD among controls. There was a significant association with the cytokine concentration of TNF-α on POD1 and duration of chest tube drainage (p < 0.05). Inflammatory cytokine levels in the pleural fluid of Fontan patients are higher compared to bi-ventricular controls and rise over time where controls do not. This suggests ongoing localized inflammation that is not a result of CPB alone and may be an important contributor to pleural drainage in patients after the Fontan procedure.

Extubation Failure Rates After Pediatric Cardiac Surgery Vary Across Hospitals.

OBJECTIVES: Many hospitals aim to extubate children early after cardiac surgery, yet it remains unclear how this practice associates with extubation failure. We evaluated adjusted extubation failure rates and duration of postoperative mechanical ventilation across hospitals and assessed cardiac ICU organizational factors associated with extubation failure. DESIGN: Secondary analysis of the Pediatric Cardiac Critical Care Consortium clinical registry. SETTING: Pediatric Cardiac Critical Care Consortium cardiac ICUs. PATIENTS: Patients with qualifying index surgical procedures from August 2014 to June 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We modeled hospital-level adjusted extubation failure rates using multivariable logistic regression. A previously validated Pediatric Cardiac Critical Care Consortium model was used to calculate adjusted postoperative mechanical ventilation. Observed-to-expected ratios for both metrics were derived for each hospital to assess performance. Hierarchical logistic regression was used to assess the association between cardiac ICU factors and extubation failure. Overall, 16,052 surgical hospitalizations were analyzed. Predictors of extubation failure (p < 0.05 in final case-mix adjustment model) included younger age, underweight, greater surgical complexity, airway anomaly, chromosomal anomaly/syndrome, longer cardiopulmonary bypass time, and other preoperative comorbidities. Three hospitals were better-than-expected outliers for extubation failure (95% CI around observed-to-expected < 1), and three hospitals were worse-than-expected (95% CI around observed-to-expected > 1). Two hospitals were better-than-expected outliers for both extubation failure and postoperative mechanical ventilation, and three were worse-than-expected for both. No hospital was an outlier in opposite directions. Greater nursing hours per patient day and percent nursing staff with critical care certification were associated with lower odds of extubation failure. Cardiac ICU factors such as fewer inexperienced nurses, greater percent critical care trained attendings, cardiac ICU-dedicated respiratory therapists, and fewer patients per cardiac ICU attending were not associated with lower odds of extubation failure. CONCLUSIONS: We saw no evidence that hospitals trade higher extubation failure rates for shorter duration of postoperative mechanical ventilation after pediatric cardiac surgery. Increasing specialized cardiac ICU nursing hours per patient day may achieve better extubation outcomes and mitigate the impact of inexperienced nurses.

Variation in Implementation and Outcomes of Early Extubation Practices After Infant Cardiac Surgery.

BACKGROUND: The Pediatric Heart Network Collaborative Learning Study (PHN CLS) increased early extubation after infant tetralogy of Fallot (TOF) and coarctation repair overall at participating sites through implementing a clinical practice guideline (CPG). We evaluated variability across sites in CPG implementation and outcomes. METHODS: Patient characteristics and outcomes (time to extubation, length of stay [LOS]) were compared across sites, including pre-CPB to post-CPG changes. Semistructured interviews were analyzed to assess similarities and differences in implementation strategies across sites. RESULTS: A total of 322 patients were included (4 active sites, 1 model site). Patient characteristics were similar across active sites, whereas pre-CPG median time to extubation varied from 15.4 to 35.5 hours. All active sites had a significant post-CPG decline (p < 0.001); however, there was variation in the post-CPG median time to extubation (0.3 to 5.3 hours, p = 0.01) and magnitude of change (-73.3% to -99.2%). Site A achieved the shortest post-CPG time to extubation and had the greatest percentage change. Two sites had significant decreases in medical ICU LOS in TOF patients; no hospital LOS changes were seen. All sites valued the collaborative learning strategy, site visits, CPG flexibility, and had similar core team composition. Site A used several unique strategies: inclusion of other staff and fellows, regular in-person data reviews, additional data collection, and creation of complementary protocols. CONCLUSIONS: All PHN CLS sites successfully reduced time to extubation. The magnitude of change varied and may be partly explained by different CPG implementation strategies. These data can guide CPG dissemination and design of future improvement projects.

A Multimethod Analysis of Pragmatic Skills in Children and Adolescents With Fragile X Syndrome, Autism Spectrum Disorder, and Down Syndrome.

Purpose: Pragmatic language skills are often impaired above and beyond general language delays in individuals with neurodevelopmental disabilities. This study used a multimethod approach to language sample analysis to characterize syndrome- and sex-specific profiles across different neurodevelopmental disabilities and to examine the congruency of 2 analysis techniques. Method: Pragmatic skills of young males and females with fragile X syndrome with autism spectrum disorder (FXS-ASD, n = 61) and without autism spectrum disorder (FXS-O, n = 40), Down syndrome (DS, n = 42), and typical development (TD, n = 37) and males with idiopathic autism spectrum disorder only (ASD-O, n = 29) were compared using variables obtained from a detailed hand-coding system contrasted with similar variables obtained automatically from the language analysis program Systematic Analysis of Language Transcripts (SALT). Results: Noncontingent language and perseveration were characteristic of the pragmatic profiles of boys and girls with FXS-ASD and boys with ASD-O. Boys with ASD-O also initiated turns less often and were more nonresponsive than other groups, and girls with FXS-ASD were more nonresponsive than their male counterparts. Hand-coding and SALT methods were largely convergent with some exceptions. Conclusion: Results suggest both similarities and differences in the pragmatic profiles observed across different neurodevelopmental disabilities, including idiopathic and FXS-associated cases of ASD, as well as an important sex difference in FXS-ASD. These findings and congruency between the 2 language sample analysis techniques together have important implications for assessment and intervention efforts.

Aspartate is an endogenous metabolic limitation for tumour growth.

Defining the metabolic limitations of tumour growth will help to develop cancer therapies1. Cancer cells proliferate slower in tumours than in standard culture conditions, indicating that a metabolic limitation may restrict cell proliferation in vivo. Aspartate synthesis can limit cancer cell proliferation when respiration is impaired2-4; however, whether acquiring aspartate is endogenously limiting for tumour growth is unknown. We confirm that aspartate has poor cell permeability, which prevents environmental acquisition, whereas the related amino acid asparagine is available to cells in tumours, but cancer cells lack asparaginase activity to convert asparagine to aspartate. Heterologous expression of guinea pig asparaginase 1 (gpASNase1), an enzyme that produces aspartate from asparagine5, confers the ability to use asparagine to supply intracellular aspartate to cancer cells in vivo. Tumours expressing gpASNase1 grow at a faster rate, indicating that aspartate acquisition is an endogenous metabolic limitation for the growth of some tumours. Tumours expressing gpASNase1 are also refractory to the growth suppressive effects of metformin, suggesting that metformin inhibits tumour growth by depleting aspartate. These findings suggest that therapeutic aspartate suppression could be effective to treat cancer.

A Multi-Method Investigation of Pragmatic Development in Individuals With Down Syndrome.

This longitudinal study examined pragmatic language in boys and girls with Down syndrome (DS) at up to three time points, using parent report, standardized and direct assessments. We also explored relationships among theory of mind, executive function, nonverbal mental age, receptive and expressive vocabulary, grammatical complexity, and pragmatic competence. Controlling for cognitive and language abilities, children with DS demonstrated greater difficulty than younger typically developing controls on parent report and standardized assessments, but only girls with DS differed on direct assessments. Further, pragmatic skills of individuals with DS developed at a delayed rate relative to controls. Some sex-specific patterns of pragmatic impairments emerged. Theory of mind and executive function both correlated with pragmatic competence. Clinical and theoretical implications are discussed.

Environment Dictates Dependence on Mitochondrial Complex I for NAD+ and Aspartate Production and Determines Cancer Cell Sensitivity to Metformin.

Metformin use is associated with reduced cancer mortality, but how metformin impacts cancer outcomes is controversial. Although metformin can act on cells autonomously to inhibit tumor growth, the doses of metformin that inhibit proliferation in tissue culture are much higher than what has been described in vivo. Here, we show that the environment drastically alters sensitivity to metformin and other complex I inhibitors. We find that complex I supports proliferation by regenerating nicotinamide adenine dinucleotide (NAD)+, and metformin's anti-proliferative effect is due to loss of NAD+/NADH homeostasis and inhibition of aspartate biosynthesis. However, complex I is only one of many inputs that determines the cellular NAD+/NADH ratio, and dependency on complex I is dictated by the activity of other pathways that affect NAD+ regeneration and aspartate levels. This suggests that cancer drug sensitivity and resistance are not intrinsic properties of cancer cells, and demonstrates that the environment can dictate sensitivity to therapies that impact cell metabolism.

Erratum to: Neural selectivity for communicative auditory signals in Phelan-McDermid syndrome.

[This corrects the article DOI: 10.1186/s11689-016-9138-9.].

Neural selectivity for communicative auditory signals in Phelan-McDermid syndrome.

BACKGROUND: Phelan-McDermid syndrome (PMS), a neurodevelopmental disorder caused by deletion or mutation in the SHANK3 gene, is one of the more common single-locus causes of autism spectrum disorder (ASD). PMS is characterized by global developmental delay, hypotonia, delayed or absent speech, increased risk of seizures, and minor dysmorphic features. Impairments in language and communication are one of the most consistent characteristics of PMS. Although there is considerable overlap in the social communicative deficits associated with PMS and ASD, there is a dearth of data on underlying abnormalities at the level of neural systems in PMS. No controlled neuroimaging studies of PMS have been reported to date. The goal of this study was to examine the neural circuitry supporting the perception of auditory communicative signals in children with PMS as compared to idiopathic ASD (iASD). METHODS: Eleven children with PMS and nine comparison children with iASD were scanned using functional magnetic resonance imaging (fMRI) under light sedation. The fMRI paradigm was a previously validated passive auditory task, which presented communicative (e.g., speech, sounds of agreement, disgust) and non-communicative vocalizations (e.g., sneezing, coughing, yawning). RESULTS: Previous research has shown that the superior temporal gyrus (STG) responds selectively to communicative vocal signals in typically developing children and adults. Here, selective activity for communicative relative to non-communicative vocalizations was detected in the right STG in the PMS group, but not in the iASD group. The PMS group also showed preferential activity for communicative vocalizations in a range of other brain regions associated with social cognition, such as the medial prefrontal cortex (MPFC), insula, and inferior frontal gyrus. Interestingly, better orienting toward social sounds was positively correlated with selective activity in the STG and other "social brain" regions, including the MPFC, in the PMS group. Finally, selective MPFC activity for communicative sounds was associated with receptive language level in the PMS group and expressive language in the iASD group. CONCLUSIONS: Despite shared behavioral features, children with PMS differed from children with iASD in their neural response to communicative vocal sounds and showed relative strengths in this area. Furthermore, the relationship between clinical characteristics and neural selectivity also differed between the two groups, suggesting that shared ASD features may partially reflect different neurofunctional abnormalities due to differing etiologies.

Supporting Aspartate Biosynthesis Is an Essential Function of Respiration in Proliferating Cells.

Mitochondrial respiration is important for cell proliferation; however, the specific metabolic requirements fulfilled by respiration to support proliferation have not been defined. Here, we show that a major role of respiration in proliferating cells is to provide electron acceptors for aspartate synthesis. This finding is consistent with the observation that cells lacking a functional respiratory chain are auxotrophic for pyruvate, which serves as an exogenous electron acceptor. Further, the pyruvate requirement can be fulfilled with an alternative electron acceptor, alpha-ketobutyrate, which provides cells neither carbon nor ATP. Alpha-ketobutyrate restores proliferation when respiration is inhibited, suggesting that an alternative electron acceptor can substitute for respiration to support proliferation. We find that electron acceptors are limiting for producing aspartate, and supplying aspartate enables proliferation of respiration deficient cells in the absence of exogenous electron acceptors. Together, these data argue a major function of respiration in proliferating cells is to support aspartate synthesis.

Erratum: A pilot controlled trial of insulin-like growth factor-1 in children with Phelan-McDermid syndrome.

[This corrects the article DOI: 10.1186/2040-2392-5-54.].

De novo SCN2A splice site mutation in a boy with Autism spectrum disorder.

BACKGROUND: SCN2A is a gene that codes for the alpha subunit of voltage-gated, type II sodium channels, and is highly expressed in the brain. Sodium channel disruptions, such as mutations in SCN2A, may play an important role in psychiatric disorders. Recently, de novo SCN2A mutations in autism spectrum disorder (ASD) have been identified. The current study characterizes a de novo splice site mutation in SCN2A that alters mRNA and protein products. CASE PRESENTATION: We describe results from clinical and genetic characterizations of a seven-year-old boy with ASD. Psychiatric interview and gold standard autism diagnostic instruments (ADOS and ADI-R) were used to confirm ASD diagnosis, in addition to performing standardized cognitive and adaptive functioning assessments (Leiter-R and Vineland Adaptive Behavior Scale), and sensory reactivity assessments (Sensory Profile and Sensory Processing Scales). Genetic testing by whole exome sequencing revealed four de novo events, including a splice site mutation c.476 + 1G > A in SCN2A, a missense mutation (c.2263G > A) causing a p.V755I change in the TLE1 gene, and two synonymous mutations (c.2943A > G in the BUB1 gene, and c.1254 T > A in C10orf68 gene). The de novo SCN2A splice site mutation produced a stop codon 10 amino acids downstream, possibly resulting in a truncated protein and/or a nonsense-mediated mRNA decay. The participant met new DSM-5 criteria for ASD, presenting with social and communication impairment, repetitive behaviors, and sensory reactivity issues. The participant's adaptive and cognitive skills fell in the low range of functioning. CONCLUSION: This report indicates that a splice site mutation in SCN2A might be contributing to the risk of ASD. Describing the specific phenotype associated with SCN2A mutations might help to reduce heterogeneity seen in ASD.