Background DDX3X syndrome is a recently identified genetic disorder that accounts for 1–3% of cases of unexplained developmental delay and/or intellectual disability (ID) in females, and is associated with motor and language delays, and autism spectrum disorder (ASD). To date, the published phenotypic characterization of this syndrome has primarily relied on medical record review; in addition, the behavioral dimensions of the syndrome have not been fully explored. Methods We carried out multi-day, prospective, detailed phenotyping of DDX3X syndrome in 14 females and 1 male, focusing on behavioral, psychological, and neurological measures. Three participants in this cohort were previously reported with limited phenotype information and were re-evaluated for this study. We compared results against population norms and contrasted phenotypes between individuals harboring either (1) protein-truncating variants or (2) missense variants or in-frame deletions. Results Eighty percent (80%) of individuals met criteria for ID, 60% for ASD and 53% for attention-deficit/hyperactivity disorder (ADHD). Motor and language delays were common as were sensory processing abnormalities. The cohort included 5 missense, 3 intronic/splice-site, 2 nonsense, 2 frameshift, 2 in-frame deletions, and one initiation codon variant. Genotype–phenotype correlations indicated that, on average, missense variants/in-frame deletions were associated with more severe language, motor, and adaptive deficits in comparison to protein-truncating variants. Limitations Sample size is modest, however, DDX3X syndrome is a rare and underdiagnosed disorder. Conclusion This study, representing a first, prospective, detailed characterization of DDX3X syndrome, extends our understanding of the neurobehavioral phenotype. Gold-standard diagnostic approaches demonstrated high rates of ID, ASD, and ADHD. In addition, sensory deficits were observed to be a key part of the syndrome. Even with a modest sample, we observe evidence for genotype–phenotype correlations with missense variants/in-frame deletions generally associated with more severe phenotypes.

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CHAMP1-related neurodevelopmental disorder, or CHAMP1 disorder, is a recently described genetic syndrome associated with developmental delay, intellectual disability, behavioral symptoms, medical comorbidities, and dysmorphic features. To date, literature has focused on medical review and dysmorphology but has yet to prospectively assess neurobehavioral core domains such as autism, or behavioral, language, cognitive, and sensory features. Here, we present deep phenotyping results for 11 individuals with CHAMP1 disorder, based on approximately 12 hours of remote clinician-administered assessments and standardized caregiver questionnaires. Diagnoses of autism spectrum disorder were given to 33% of participants; repetitive behaviors and sensory-seeking symptoms were prominent in this cohort. In addition, 60% of participants met the criteria for attention-deficit/hyperactivity disorder (ADHD). High rates of ADHD and relatively low rates of treatment suggest potential areas for intervention. This study represents the first prospective phenotyping analysis of individuals with CHAMP1 disorder. The utility of specific measures as clinical endpoints, as well as benefits and limitations of remote phenotyping, are described.

Background Phelan-McDermid syndrome (PMS) is caused by haploinsufficiency of the SHANK3 gene and is characterized by global developmental delays and autism spectrum disorder (ASD). Based on several converging lines of preclinical and clinical evidence supporting the use of insulin-like growth factor-1 (IGF-1) in PMS, this study aims to follow-up a previous pilot study with IGF-1 to further evaluate this novel therapeutic for core symptoms of ASD in children with PMS. Methods Ten children aged 5–9 with PMS were enrolled. Participants were randomized to receive IGF-1 or placebo (saline) using a 12-week, double-blind, crossover design. Efficacy was assessed using the primary outcome of the Aberrant Behavior Checklist—Social Withdrawal (ABC-SW) subscale as well as secondary outcome measures reflecting core symptoms of ASD. To increase power and sample size, we jointly analyzed the effect of IGF-1 reported here together with results from our previous controlled trail of IGF-1 in children with PMS (combined N = 19). Results Results on the ABC-SW did not reach statistical significance, however significant improvements in sensory reactivity symptoms were observed. In our pooled analyses, IGF-1 treatment also led to significant improvements in repetitive behaviors and hyperactivity. There were no other statistically significant effects seen across other clinical outcome measures. IGF-1 was well tolerated and there were no serious adverse events. Limitations The small sample size and expectancy bias due to relying on parent reported outcome measures may contribute to limitations in interpreting results. Conclusion IGF-1 is efficacious in improving sensory reactivity symptoms, repetitive behaviors, and hyperactivity  in children with PMS. Trial registration NCT01525901.