The neurobehavioral and molecular phenotype of Angelman Syndrome.

Angelman Syndrome (AS) is a rare neurodevelopmental disorder associated with developmental delay, speech impairment, gait ataxia, and a unique behavioral profile. AS is caused by loss of maternal expression of the paternally imprinted UBE3A gene. In this study we aim to contribute to understanding of the neurobehavioral phenotype of AS with particular focus on the neuropsychiatric presentation of the disorder. We also undertake initial exploration of brain-derived neurotrophic factor (BDNF) plasma levels in AS. Twelve individuals ages 3 years or older with a confirmed genetic diagnosis of AS underwent detailed medical history, phenotypic characterization, and BDNF plasma sampling. The results of this study demonstrate that individuals with AS suffer from significant developmental delay, impaired adaptive behavior, and sleep disruption. Additionally, hyperactivity/impulsivity appears to be the primary behavioral domain noted in these individuals. The majority of individuals in this project met criteria for autism spectrum disorder on the Autism Diagnostic Observation Schedule (ADOS); however, a negative correlation was noted between ADOS score and developmental age. BDNF plasma levels in AS individuals were significantly elevated compared to neurotypical controls. This is the first report of abnormal BDNF levels in AS, and one that necessitates larger future studies. The results provide a clue to understanding abnormal neuronal development in AS and may help guide future AS research.

A randomized double-blind, placebo-controlled pilot trial of mirtazapine for anxiety in children and adolescents with autism spectrum disorder.

This study was a 10-week double-blind, placebo-controlled pilot trial of mirtazapine for anxiety in youth with autism spectrum disorder (ASD). Participants were ages 5 to 17 years with ASD and clinically significant anxiety (Pediatric Anxiety Rating Scale [PARS] score ≥10). Thirty participants were randomized to mirtazapine (7.5-45 mg/day) or placebo in a 2:1 ratio. The co-primary outcome measures were the PARS and the Clinical Global Impressions-Improvement subscale (CGI-I). Mirtazapine resulted in a statistically significant within group decrease in anxiety on the PARS (ES 1.76, p < 0.001). The improvement in PARS score for mirtazapine versus placebo was clinically meaningful but not statistically significant (ES = 0.63, p = 0.64). Forty-seven percent of participants assigned to mirtazapine (95% CI 22%: 74%) and 20% assigned to placebo (95% CI 2%: 60%) were rated "much improved" (CGI-I = 2) or "very much improved" (CGI-I = 1) for anxiety, p = 0.46. No statistically significant differences in mean 10-week changes between mirtazapine and placebo occurred on any outcome measure. There were no statistically significant differences in adverse effect frequency between mirtazapine and placebo. The results are consistent with mirtazapine's safety and tolerability and meet three of four pre-specified indicators of efficacy (statistically significant change in total PARS score for mirtazapine, numerically greater reduction in total PARS score for mirtazapine than placebo, numerically higher number of responders to mirtazapine than placebo, but not greater than 50% of participants receiving mirtazapine rated as responders). Implementation of a larger randomized controlled trial of mirtazapine for the treatment of anxiety in this population is supported.Clinical trial registration information: Mirtazapine Treatment of Anxiety in Children and Adolescents with Pervasive Developmental Disorders; https://clinicaltrials.gov ; NCT01302964.

Brief report: Pilot single-blind placebo lead-in study of acamprosate in youth with autistic disorder.

RATIONALE: An excitatory/inhibitory (E:I) imbalance marked by enhanced glutamate and deficient gamma-aminobutyric acid (GABA) neurotransmission may contribute to the pathophysiology of autism spectrum disorders (ASD). OBJECTIVES: We report on the first single-blind placebo lead-in trial of acamprosate, a drug with putative mechanisms restoring E:I imbalance, in twelve youth with ASD. MATERIALS AND METHODS: We conducted a 12-week single-blind, placebo lead-in study of acamprosate in youth age 5-17 years with autistic disorder. RESULTS: Six of nine subjects who received active drug treatment were deemed treatment responders (defined by a score at final visit of "very much improved" or "much improved" on the Clinical Global Impressions Improvement scale) and ≥25% improvement on the Aberrant Behavior Checklist Social Withdrawal subscale. CONCLUSION: Future larger-scale dose finding studies of acamprosate in ASD may be warranted given this preliminary indication of benefit.

Impact of acamprosate on behavior and brain-derived neurotrophic factor: an open-label study in youth with fragile X syndrome.

RATIONALE: Fragile X syndrome (FXS) is an inherited form of developmental disability and a single gene cause of autism. As a disorder with increasingly understood pathophysiology, FXS is a model form of developmental disability for targeted drug development efforts. Preclinical animal model findings have focused targeted drug treatment development in FXS on an imbalance between excessive glutamate and deficient gamma-aminobutyric acid (GABA) neurotransmission. METHODS: We conducted a prospective open-label 10-week trial of acamprosate in 12 youth aged 6-17 years (mean age: 11.9 years) with FXS. RESULTS: Acamprosate use (mean dose: 1,054 ± 422 mg/day) was associated with treatment response (defined by a Clinical Global Impressions Improvement (CGI-I) scale score of "very much improved" or "much improved") in nine of 12 (75 %) subjects. Improvement was noted in social behavior and inattention/hyperactivity using multiple standard behavioral outcome measures. No significant adverse effects or changes in vital signs, including weight or laboratory measures, occurred during treatment with acamprosate. Additionally, pre- and post-treatment blood biomarker analyses looking at brain-derived neurotrophic factor (BDNF) levels found a significant increase in BDNF with treatment. In our pilot sample, treatment response did not correlate with change in BDNF with treatment. CONCLUSIONS: Acamprosate was generally safe and well tolerated and was associated with a significant improvement in social behavior and a reduction in inattention/hyperactivity. The increase in BDNF that occurred with treatment may be a useful pharmacodynamic marker in future acamprosate studies. Given these findings, a double-blind, placebo-controlled study of acamprosate in youth with FXS is warranted.