David Grodberg

Prospective investigation of autism and genotype-phenotype correlations in 22q13 deletion syndrome and SHANK3 deficiency

Background22q13 deletion syndrome, also known as Phelan-McDermid syndrome, is a neurodevelopmental disorder characterized by intellectual disability, hypotonia, delayed or absent speech, and autistic features. SHANK3 has been identified as the critical gene in the neurological and behavioral aspects of this syndrome. The phenotype of SHANK3 deficiency has been described primarily from case studies, with limited evaluation of behavioral and cognitive deficits. The present study used a prospective design and inter-disciplinary clinical evaluations to assess patients with SHANK3 deficiency, with the goal of providing a comprehensive picture of the medical and behavioral profile of the syndrome.MethodsA serially ascertained sample of patients with SHANK3 deficiency (n = 32) was evaluated by a team of child psychiatrists, neurologists, clinical geneticists, molecular geneticists and psychologists. Patients were evaluated for autism spectrum disorder using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule-G.ResultsThirty participants with 22q13.3 deletions ranging in size from 101 kb to 8.45 Mb and two participants with de novo SHANK3 mutations were included. The sample was characterized by high rates of autism spectrum disorder: 27 (84%) met criteria for autism spectrum disorder and 24 (75%) for autistic disorder. Most patients (77%) exhibited severe to profound intellectual disability and only five (19%) used some words spontaneously to communicate. Dysmorphic features, hypotonia, gait disturbance, recurring upper respiratory tract infections, gastroesophageal reflux and seizures were also common. Analysis of genotype-phenotype correlations indicated that larger deletions were associated with increased levels of dysmorphic features, medical comorbidities and social communication impairments related to autism. Analyses of individuals with small deletions or point mutations identified features related to SHANK3 haploinsufficiency, including ASD, seizures and abnormal EEG, hypotonia, sleep disturbances, abnormal brain MRI, gastroesophageal reflux, and certain dysmorphic features.ConclusionsThis study supports findings from previous research on the severity of intellectual, motor, and speech impairments seen in SHANK3 deficiency, and highlights the prominence of autism spectrum disorder in the syndrome. Limitations of existing evaluation tools are discussed, along with the need for natural history studies to inform clinical monitoring and treatment development in SHANK3 deficiency.

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.].

Functional deficits of the attentional networks in autism

Attentional dysfunction is among the most consistent observations of autism spectrum disorders (ASD). However, the neural nature of this deficit in ASD is still unclear. In this study, we aimed to identify the neurobehavioral correlates of attentional dysfunction in ASD. We used the Attention Network Test‐Revised and functional magnetic resonance imaging to examine alerting, orienting, and executive control functions, as well as the neural substrates underlying these attentional functions in unmedicated, high‐functioning adults with ASD (n = 12) and matched healthy controls (HC, n = 12). Compared with HC, individuals with ASD showed increased error rates in alerting and executive control, accompanied by lower activity in the mid‐frontal gyrus and the caudate nucleus for alerting, and by the absence of significant functional activation in the anterior cingulate cortex (ACC) for executive control. In addition, greater behavioral deficiency in executive control in ASD was correlated with less functional activation of the ACC. These findings of behavioral and neural abnormalities in alerting and executive control of attention in ASD may suggest core attentional deficits, which require further investigation.

Brief Report: The Autism Mental Status Examination--Development of a Brief Autism-Focused Exam.

The Autism Mental Status Examination (AMSE) described here is an eight-item observational assessment that prompts the observation and recording of signs and symptoms of autism spectrum disorders (ASD). The AMSE is intended to take place seamlessly in the context of a clinical exam and produces a total score. Subjects were independently administered the AMSE and the Autism Diagnostic Observation Schedule (ADOS). The ADOS was used to estimate the most effective criterion cut-off on the AMSE. A score of five or greater produced excellent sensitivity and good specificity in a high-risk sample. Internal consistency was acceptable and inter-rater reliability was good to excellent. Preliminary findings indicate excellent classification accuracy and suggest that the AMSE provides a rapid and reliable observational assessment in a high-risk population.

Analysis of a purported SHANK3 mutation in a boy with autism: clinical impact of rare variant research in neurodevelopmental disabilities.

There is strong evidence for rare, highly penetrant genetic variants playing an etiological role in multiple neurodevelopmental disabilities, including autism spectrum disorders. The rate of discovery of such rare variants is increasing with the advent of larger sample collections, chromosome microarray analyses, and high-throughput sequencing. As the variants that are being discovered can be highly penetrant, they lead immediately to model systems with construct validity, critical for understanding the underlying neurobiology of these conditions, which in turn can provide leads for novel therapeutic targets. Moreover, these discoveries can benefit families with information about recurrence risk, resolve concerns about etiology, provide information about associated medical issues, and engender directed advocacy for specific genetic conditions. For these reasons, diagnostic laboratories are taking advantage of research data as they are produced. In the current report, we present our molecular analysis of a child with a purported disruptive mutation in SHANK3 identified by a commercial genetic testing laboratory and we provide evidence that this was not an etiological variant. The variant was a 1-bp insertion in exon 11 of the RefSeq gene, which we then determined was inherited from a healthy mother and found in ~1% of controls. Since the variant would be predicted to disrupt the reference gene, and the penetrance of SHANK3 mutations is very high, we did follow up molecular and bioinformatic analyses and concluded that the presumptive exon containing the variant is not likely to be present in most or all SHANK3 transcripts. The results highlight difficulties that can arise with rapid translation of research findings to clinical practice. Researchers are in a unique position to generate resources with collated and curated information that can inform research, genetic testing, clinicians, and families about the best practices as pertains to rare genetic variants in neurodevelopmental disabilities. Of immediate importance would be a well-curated database of gene variation identified in large numbers of typically developing individuals and in individuals affected with neurodevelopmental disabilities. Such a database would reduce false-positive results in clinical settings, would be helpful in structure-function analyses, and would direct translational research to pathways most likely to benefit families.

The Autism Mental Status Exam: Sensitivity and Specificity Using DSM-5 Criteria for Autism Spectrum Disorder in Verbally Fluent Adults

The phenotypic heterogeneity of adults suspected of autism spectrum disorder (ASD) requires a standardized diagnostic approach that is feasible in all clinical settings. The autism mental status exam (AMSE) is an eight-item observational assessment that structures the observation and documentation of social, communicative and behavioral signs and symptoms of ASD. Previous findings indicate high classification accuracy when compared to the autism diagnostic observation schedule in a non-stratified population of high-risk patients suspected of having ASD. This protocol investigates the sensitivity and specificity of AMSE scores using DSM-5 criteria for ASD in a sample of high-risk verbally fluent adults. Findings indicate an optimized sensitivity of 0.91 and a specificity of 0.93 for this group. Because of its high clinical utility, the AMSE holds promise as a diagnostic assessment tool that can support one’s clinical diagnosis of ASD in high-risk adults.

Complex autism spectrum disorder in a patient with a 17q12 microduplication.

Autism spectrum disorders (ASDs) are phenotypically complex developmental neuropsychiatric disorders affecting approximately 0.6% of the population. About 30–70% of affected children are also considered to have intellectual disability (ID). The underlying genetic causes of ASDs are diverse with a defined etiology in 16–20%. Array comparative genomic hybridization (aCGH) has proven useful in identifying sub‐microscopic chromosome aberrations in a subset of patients, some of which have been shown to be recurrent. One such aberration is the 1.4 Mb microdeletion at chromosome 17q12, which has been reported to be associated with renal disease, growth restriction, diabetes, cognitive impairment, seizures, and in some cases an ASD. Patients with the reciprocal chromosome 17q12 microduplication typically have also been identified with ID and in some cases seizures and behavioral abnormalities. Here we report a patient with a de novo, 1.4 Mb microduplication diagnosed with significant ID involving complex deficits and autism. To our knowledge, this is the first report of a patient with the 17q12 microduplication and a complex ASD 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.