Paige M. Siper

Prospective investigation of FOXP1 syndrome

BackgroundHaploinsufficiency of the forkhead-box protein P1 (FOXP1) gene leads to a neurodevelopmental disorder termed FOXP1 syndrome. Previous studies in individuals carrying FOXP1 mutations and deletions have described the presence of autism spectrum disorder (ASD) traits, intellectual disability, language impairment, and psychiatric features. The goal of the present study was to comprehensively characterize the genetic and clinical spectrum of FOXP1 syndrome. This is the first study to prospectively examine the genotype-phenotype relationship in multiple individuals with FOXP1 syndrome, using a battery of standardized clinical assessments.MethodsGenetic and clinical data was obtained and analyzed from nine children and adolescents between the ages of 5–17 with mutations in FOXP1. Phenotypic characterization included gold standard ASD testing and norm-referenced measures of cognition, adaptive behavior, language, motor, and visual-motor integration skills. In addition, psychiatric, medical, neurological, and dysmorphology examinations were completed by a multidisciplinary team of clinicians. A comprehensive review of reported cases was also performed. All missense and in-frame mutations were mapped onto the three-dimensional structure of DNA-bound FOXP1.ResultsWe have identified nine de novo mutations, including three frameshift, one nonsense, one mutation in an essential splice site resulting in frameshift and insertion of a premature stop codon, three missense, and one in-frame deletion. Reviewing prior literature, we found seven instances of recurrent mutations and another 34 private mutations. The majority of pathogenic missense and in-frame mutations, including all four missense mutations in our cohort, lie in the DNA-binding domain. Through structural analyses, we show that the mutations perturb amino acids necessary for binding to the DNA or interfere with the domain swapping that mediates FOXP1 dimerization. Individuals with FOXP1 syndrome presented with delays in early motor and language milestones, language impairment (expressive language > receptive language), ASD symptoms, visual-motor integration deficits, and complex psychiatric presentations characterized by anxiety, obsessive-compulsive traits, attention deficits, and externalizing symptoms. Medical features included non-specific structural brain abnormalities and dysmorphic features, endocrine and gastrointestinal problems, sleep disturbances, and sinopulmonary infections.ConclusionsThis study identifies novel FOXP1 mutations associated with FOXP1 syndrome, identifies recurrent mutations, and demonstrates significant clustering of missense mutations in the DNA-binding domain. Clinical findings confirm the role FOXP1 plays in development across multiple domains of functioning. The genetic findings can be incorporated into clinical genetics practice to improve accurate genetic diagnosis of FOXP1 syndrome and the clinical findings can inform monitoring and treatment of individuals with FOXP1 syndrome.

A clinician-administered observation and corresponding caregiver interview capturing DSM-5 sensory reactivity symptoms in children with ASD

Background: Sensory reactivity is a new criterion for autism spectrum disorder (ASD) in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‐5). However, there is no consensus on how to reliably measure sensory reactivity, particularly in minimally verbal individuals. The current study is an initial validation of the Sensory Assessment for Neurodevelopmental Disorders (SAND), a novel clinician‐administered observation and corresponding caregiver interview that captures sensory symptoms based on DSM‐5 criteria for ASD. Methods: Eighty children between the ages of 2 and 12 participated in this study; 44 children with ASD and 36 typically developing (TD) children. Sensory reactivity symptoms were measured using the SAND and the already validated Short Sensory Profile (SSP). Initial psychometric properties of the SAND were examined including reliability, validity, sensitivity and specificity. Results: Children with ASD showed significantly more sensory reactivity symptoms compared to TD children across sensory domains (visual, tactile, and auditory) and within sensory subtypes (hyperreactivity, hyporeactivity and seeking). The SAND showed strong internal consistency, inter‐rater reliability and test‐retest reliability, high sensitivity (95.5%) and specificity (91.7%), and strong convergent validity with the SSP. Significance: The SAND provides a novel method to characterize sensory reactivity symptoms based on DSM‐5 criteria for ASD. This is the first known sensory assessment that combines a clinician‐administered observation and caregiver interview to optimally capture sensory phenotypes characteristic of individuals with neurodevelopmental disorders. The SAND offers a beneficial new tool for both research and clinical purposes and has the potential to meaningfully enhance gold‐standard assessment of ASD. Autism Res 2017, 10: 1133–1140.

Neural selectivity for communicative auditory signals in Phelan-McDermid syndrome

BackgroundPhelan-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).MethodsEleven 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).ResultsPrevious 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.ConclusionsDespite 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.

Examining the Efficacy of a Family Peer Advocate Model for Black and Hispanic Caregivers of Children with Autism Spectrum Disorder

Autism spectrum disorder (ASD) affects individuals across all racial and ethnic groups, yet rates of diagnosis are disproportionately higher for Black and Hispanic children. Caregivers of children with ASD experience significant stressors, which have been associated with parental strain, inadequate utilization of mental health services and lower quality of life. The family peer advocate (FPA) model has been utilized across service delivery systems to provide family-to-family support, facilitate engagement, and increase access to care. This study used a randomized controlled design to examine the efficacy of FPAs in a racially and ethnically diverse sample. Results demonstrate significantly increased knowledge of ASD and reduced levels of stress for caregivers who received the FPA intervention as compared to treatment as usual.

Rapid and Objective Assessment of Neural Function in Autism Spectrum Disorder Using Transient Visual Evoked Potentials.

Objective There is a critical need to identify biomarkers and objective outcome measures that can be used to understand underlying neural mechanisms in autism spectrum disorder (ASD). Visual evoked potentials (VEPs) offer a noninvasive technique to evaluate the functional integrity of neural mechanisms, specifically visual pathways, while probing for disease pathophysiology. Methods Transient VEPs (tVEPs) were obtained from 96 unmedicated children, including 37 children with ASD, 36 typically developing (TD) children, and 23 unaffected siblings (SIBS). A conventional contrast-reversing checkerboard condition was compared to a novel short-duration condition, which was developed to enable objective data collection from severely affected populations who are often excluded from electroencephalographic (EEG) studies. Results Children with ASD showed significantly smaller amplitudes compared to TD children at two of the earliest critical VEP components, P60-N75 and N75-P100. SIBS showed intermediate responses relative to ASD and TD groups. There were no group differences in response latency. Frequency band analyses indicated significantly weaker responses for the ASD group in bands encompassing gamma-wave activity. Ninety-two percent of children with ASD were able to complete the short-duration condition compared to 68% for the standard condition. Conclusions The current study establishes the utility of a short-duration tVEP test for use in children at varying levels of functioning and describes neural abnormalities in children with idiopathic ASD. Implications for excitatory/inhibitory balance as well as the potential application of VEP for use in clinical trials are discussed.

Brief Report: Sensory Reactivity in Children with Phelan-McDermid Syndrome.

Phelan–McDermid syndrome (PMS), a monogenic form of autism spectrum disorder (ASD), results from deletion or mutation of the SHANK3 gene. Atypical sensory reactivity is now included in the diagnostic criteria for ASD. Examining the sensory phenotype in monogenic forms of ASD, such as PMS, may help identify underlying mechanisms of sensory reactivity. Using the Short Sensory Profile, the current study compared sensory reactivity in 24 children with PMS to 61 children with idiopathic ASD (iASD). Results suggest that children with PMS show more low energy/weak symptoms and less sensory sensitivity as compared to children with iASD. This study is the first to demonstrate differences in sensory reactivity between children with PMS and iASD, helping to refine the PMS phenotype.

A Simplified Diagnostic Observational Assessment of Autism Spectrum Disorder in Early Childhood.

Subspecialty physicians who have expertise in the diagnosis of autism spectrum disorder typically do not have the resources to administer comprehensive diagnostic observational assessments for patients suspected of ASD. The autism mental status exam (AMSE) is a free and brief eight‐item observation tool that addresses this practice gap. The AMSE, designed by Child and Adolescent Psychiatrists, Developmental Behavioral Pediatricians and Pediatric Neurologists structures the observation and documentation of signs and symptoms of ASD and yields a score. Excellent sensitivity and specificity was demonstrated in a population of high‐risk adults. This protocol now investigates the AMSEs test performance in a population of 45 young children age 18 months to 5 years with suspected ASD or social and communication concerns who are evaluated at an autism research center. Each subject received a developmental evaluation, including the AMSE, performed by a Child and Adolescent Psychiatrist, that was followed by independent standardized assessment using the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview‐Revised. A Best Estimate Diagnosis protocol used DSM‐5 criteria to ascertain a diagnosis of ASD or non‐ASD. Receiver operating characteristic curve analysis was used to determine the AMSE cut point with the highest sensitivity and specificity. Findings indicate an optimized sensitivity of 94% and a specificity of 100% for this high prevalence group. Because of its high classification accuracy in this sample of children the AMSE holds promise as a tool that can support both diagnostic decision making and standardize point of care observational assessment of ASD in high risk children. Autism Res 2016, 9: 443–449.

Delineation of the genetic and clinical spectrum of Phelan-McDermid syndrome caused by SHANK3 point mutations

BackgroundPhelan-McDermid syndrome (PMS) is a neurodevelopmental disorder characterized by psychiatric and neurological features. Most reported cases are caused by 22q13.3 deletions, leading to SHANK3 haploinsufficiency, but also usually encompassing many other genes. While the number of point mutations identified in SHANK3 has increased in recent years due to large-scale sequencing studies, systematic studies describing the phenotype of individuals harboring such mutations are lacking.MethodsWe provide detailed clinical and genetic data on 17 individuals carrying mutations in SHANK3. We also review 60 previously reported patients with pathogenic or likely pathogenic SHANK3 variants, often lacking detailed phenotypic information.ResultsSHANK3 mutations in our cohort and in previously reported cases were distributed throughout the protein; the majority were truncating and all were compatible with de novo inheritance. Despite substantial allelic heterogeneity, four variants were recurrent (p.Leu1142Valfs*153, p.Ala1227Glyfs*69, p.Arg1255Leufs*25, and c.2265+1G>A), suggesting that these are hotspots for de novo mutations. All individuals studied had intellectual disability, and autism spectrum disorder was prevalent (73%). Severe speech deficits were common, but in contrast to individuals with 22q13.3 deletions, the majority developed single words, including 41% with at least phrase speech. Other common findings were consistent with reports among individuals with 22q13.3 deletions, including hypotonia, motor skill deficits, regression, seizures, brain abnormalities, mild dysmorphic features, and feeding and gastrointestinal problems.ConclusionsHaploinsufficiency of SHANK3 resulting from point mutations is sufficient to cause a broad range of features associated with PMS. Our findings expand the molecular and phenotypic spectrum of PMS caused by SHANK3 point mutations and suggest that, in general, speech impairment and motor deficits are more severe in the case of deletions. In contrast, renal abnormalities associated with 22q13.3 deletions do not appear to be related to the loss of SHANK3.

Detecting Autism Spectrum Disorder in Children With ADHD and Social Disability.

Objective: The social disability associated with ADHD often makes diagnostic and treatment decision making challenging. This protocol investigates the test performance of the Autism Mental Status Exam (AMSE) in detecting autism spectrum disorder (ASD) in a sample of 45 children with ADHD and ASD symptomatology. The AMSE is a brief ASD diagnostic assessment administered in the context of a clinical exam. Method: All participants received a developmental evaluation, including the AMSE, followed by independent gold standard diagnostic assessments including the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview–Revised (ADI-R). Results: Receiver operating characteristics (ROC) curve analysis indicated strong sensitivity and specificity in this population. Optimal cutoff scores are provided. Conclusion: The AMSE holds promise as a brief ASD assessment tool for children with ADHD and ASD symptomatology and as a guide for treatment and referral decisions at the point of care.

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

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