Maladaptive behaviors in individuals with Angelman syndrome.

Maladaptive behaviors are challenging and a source of stress for caregivers of individuals with Angelman Syndrome (AS). There is limited information on how these maladaptive behaviors vary over time among individuals with AS due to different genetic etiologies. In this study, caregivers of 301 individuals with AS were asked questions about their child's behavior and completed the Aberrant Behavior Checklist-Community version (ABC-C). Developmental functioning was evaluated with either the Bayley Scales of Infant Development, Third Edition (Bayley-III) or the Mullen Scales of Early Learning (MSEL). Family functioning was assessed using the parent-completed Parenting Stress Index (PSI) and the Family Quality of Life questionnaire (FQoL). Approximately 70% of participants had AS due to a deletion on the maternally-inherited copy of chromosome 15q11q13. Results revealed that at baseline, individuals with AS had low scores in the domains of lethargy (mean: 2.6-4.2 depending on genotype) and stereotypy (mean: 2.3-4.2 depending on genotype). Higher cognitive functioning was associated with increased irritability (r = 0.32, p < .01). Hyperactivity (p < .05) and irritability (p < .05) increased with age across all genotypes and should be ongoing targets for both behavioral and pharmacological treatment. Concerns for short attention span were endorsed by more than 70% of caregivers at baseline. Maladaptive behaviors, particularly hyperactivity, irritability and aggression, adversely affected parental stress, and family quality of life.

A randomized controlled trial of levodopa in patients with Angelman syndrome.

Treatment for Angelman syndrome (AS) is currently limited to symptomatic interventions. A mouse model of AS has reduced calcium/calmodulin-dependent kinase II activity due to excessive phosphorylation of specific threonine residues, leading to diminished long-term potentiation. In a rat model of Parkinson disease, levodopa reduced phosphorylation of various proteins, including calcium/calmodulin-dependent kinase II. Further studies demonstrated that AS mice treated with levodopa performed better on rotarod testing than untreated AS mice. We conducted a multi-center double-blind randomized placebo-controlled 1-year trial of levodopa / carbidopa with either 10 or 15 mg/kg/day of levodopa in children with AS. The outcome of this intervention was assessed using either the Bayley Scales of Infant Development or the Mullen Scales of Early Learning, as well as the Vineland Adaptive Behavior Scales, and the Aberrant Behavior Checklist. Of the 78 participants enrolled, 67 participants received study medication (33 on levodopa, 34 on placebo), and 55 participants (29 on levodopa, 26 on placebo) completed the 1-year study. There were no clinically or statistically significant changes in any of the outcome measures over a 1-year period comparing the levodopa and placebo groups. The number of adverse events reported, including the more serious adverse events, was similar in both groups, but none were related to treatment with levodopa. Our data demonstrate that levodopa is well-tolerated by children with AS. However, in the doses used in this study, it failed to improve their neurodevelopment or behavioral outcome.

Adaptive Skills of Individuals with Angelman Syndrome Assessed Using the Vineland Adaptive Behavior Scales, 2nd Edition.

In the current study, we examined adaptive skills and trajectories over time in 257 individuals with Angelman syndrome (AS) using the Vineland Adaptive Behavior Scales, 2nd Edition. Multilevel linear models were used to examine differences between molecular subtypes over time, from one year to 13 years of age, in the adaptive domains of communication, daily living skills, socialization and motor skills. Individuals with non-deletion subtypes typically demonstrated a higher level of adaptive skills compared to those with deletion subtypes. Statistically significant growth was observed in all adaptive domains through at least early adolescence. Individuals with AS should continue to receive developmental services and educational supports through adolescence and into adulthood given the slow rates of growth being observed across adaptive domains.

Developmental Skills of Individuals with Angelman Syndrome Assessed Using the Bayley-III.

We describe the development of 236 children with Angelman syndrome (AS) using the Bayley Scales of Infant and Toddler Development, Third Edition. Multilevel linear mixed modeling approaches were used to explore differences between molecular subtypes and over time. Individuals with AS continue to make slow gains in development through at least age 12 years of age at about 1-2 months/year based on age equivalent score and 1-16 growth score points/year depending on molecular subtype and domain. Children with a deletion have lower scores at baseline and slower rate of gaining skills while children with UBE3A variant subtype demonstrated higher scores as well as greater rates of skill attainment in all domains. The developmental profiles of UPD and ImpD were similar.

Longitudinal follow-up of autism spectrum features and sensory behaviors in Angelman syndrome by deletion class.

BACKGROUND: Angelman syndrome (AS) is a neurogenetic disorder characterized by severe intellectual disability, lack of speech, and low threshold for laughter; it is considered a 'syndromic' form of autism spectrum disorder (ASD). Previous studies have indicated overlap of ASD and AS, primarily in individuals with larger (∼6 Mb) Class I deletions of chromosome 15q11-13. Questions remain regarding whether intellectual disability solely contributes to ASD features in AS and how ASD features in AS change over time. In this study, we used a dimensional approach to examine ASD symptom severity in individuals with AS Class I versus Class II deletions within the context of cognitive development over time. METHODS: A total of 17 participants with a larger, Class I deletion and 25 participants with a smaller Class II deletion (∼5 Mb) were enrolled (age range = 2-25 years; 5 years 5 months). Standardized measures of cognition, language, motor skills, adaptive skills, maladaptive behavior, autism, and sensory-seeking behaviors/aversions were given at baseline and after 12 months. RESULTS: Despite equivalent cognition and adaptive behavior, the results of repeated measures analyses of variance indicate that participants with Class I deletions have greater impairment in social affect (F = 8.65; p = .006) and more repetitive behaviors (F = 7.92; p = .008) compared to participants with Class II deletions. Although both groups improve in cognition over time, differences in ASD behaviors persist. CONCLUSIONS: Despite a lack of differences in cognition or adaptive behavior, individuals with Class I deletions have greater severity in ASD features and sensory aversions that remain over time. There are four genes (NIPA 1, NIPA 2, CYFIP1, and GCP5) missing in Class I and present in Class Il deletions, one or more of which may have a role in modifying the severity of social affect impairment, and level of restricted/repetitive behaviors in AS. Our results also suggest the utility of a dimensional, longitudinal approach to the assessment of ASD features in populations of individuals who are low functioning.

Deletions of NRXN1 (neurexin-1) predispose to a wide spectrum of developmental disorders.

Research has implicated mutations in the gene for neurexin-1 (NRXN1) in a variety of conditions including autism, schizophrenia, and nicotine dependence. To our knowledge, there have been no published reports describing the breadth of the phenotype associated with mutations in NRXN1. We present a medical record review of subjects with deletions involving exonic sequences of NRXN1. We ascertained cases from 3,540 individuals referred clinically for comparative genomic hybridization testing from March 2007 to January 2009. Twelve subjects were identified with exonic deletions. The phenotype of individuals with NRXN1 deletion is variable and includes autism spectrum disorders, mental retardation, language delays, and hypotonia. There was a statistically significant increase in NRXN1 deletion in our clinical sample compared to control populations described in the literature (P = 8.9 x 10(-7)). Three additional subjects with NRXN1 deletions and autism were identified through the Homozygosity Mapping Collaborative for Autism, and this deletion segregated with the phenotype. Our study indicates that deletions of NRXN1 predispose to a wide spectrum of developmental disorders.

A Prospective Study of the Concordance of DSM-IV and DSM-5 Diagnostic Criteria for Autism Spectrum Disorder.

The transition from DSM-IV to DSM-5 criteria for autism spectrum disorder (ASD) sparked considerable concern about the potential implications of these changes. This study was designed to address limitations of prior studies by prospectively examining the concordance of DSM-IV and final DSM-5 criteria on a consecutive sample of 439 children referred for autism diagnostic evaluations. Concordance and discordance were assessed using a consistent diagnostic battery. DSM-5 criteria demonstrated excellent overall specificity and good sensitivity relative to DSM-IV criteria. Sensitivity and specificity were strongest for children meeting DSM-IV criteria for autistic disorder, but poor for those meeting criteria for Asperger's disorder and pervasive developmental disorder. Higher IQ, older age, female sex, and less pronounced ASD symptoms were associated with greater discordance.

Relationship Between Subtypes of Restricted and Repetitive Behaviors and Sleep Disturbance in Autism Spectrum Disorder.

We examined the association of two types of restricted and repetitive behaviors, repetitive sensory motor (RSM) and insistence on sameness (IS), with sleep problems in children with autism spectrum disorder (ASD). Participants included 532 children (aged 2-17) who participated in the Autism Speaks Autism Treatment Network research registry. Confirmatory factor analysis of the Autism Diagnostic Interview-Revised detected the presence of RSM and IS. RSM behaviors were positively associated with parent-reported sleep problems, and this relationship remained significant after controlling for anxiety symptoms. IS was not significantly associated with sleep problems. Better understanding of the relationship between specific types of repetitive behaviors and sleep problems may allow providers to tailor interventions to the individual presentations of their patients with ASD.

A Rare Inherited 15q11.2-q13.1 Interstitial Duplication with Maternal Somatic Mosaicism, Renal Carcinoma, and Autism.

Chromosome 15q11-q13.1 duplication is a common copy number variant associated with autism spectrum disorder (ASD). Most cases are de novo, maternal in origin and fully penetrant for ASD. Here, we describe a unique family with an interstitial 15q11.2-q13.1 maternal duplication and the presence of somatic mosaicism in the mother. She is typically functioning, but formal autism testing showed mild ASD. She had several congenital anomalies, and she is the first 15q Duplication case reported in the literature to develop unilateral renal carcinoma. Her two affected children share some of these clinical characteristics, and have severe ASD. Several tissues in the mother, including blood, skin, a kidney tumor, and normal kidney margin tissues were studied for the presence of the 15q11-q13.1 duplication. We show the mother has somatic mosaicism for the duplication in several tissues to varying degrees. A growth competition assay in two types of stem cells from duplication 15q individuals was also performed. Our results suggest that the presence of this interstitial duplication 15q chromosome may confer a previously unknown growth advantage in this particular individual, but not in the general interstitial duplication 15q population.

Expression of the broad autism phenotype in simplex autism families from the Simons Simplex Collection.

The broad autism phenotype (BAP) refers to the phenotypic expression of an underlying genetic liability to autism, manifest in non-autistic relatives. This study examined the relationship among the Broad Autism Phenotype Questionnaire (BAPQ), Social Responsiveness Scale: Adult Research Version (SRS:ARV), and Family History Interview (FHI) in a large, multi-site study of 1,650 simplex families (Simons Simplex Collection). Correlations between the BAPQ and SRS:ARV Total scores were moderate, and correlations between FHI ratings and SRS:ARV and BAPQ were significant but weak. Overall, the results suggested that BAP traits occur at low rates in simplex families, and rates vary significantly depending upon the measure utilized. Implications include the need for multiple informants, and the assessment of distinct BAP traits in large-scale genetic studies of individuals with ASD.

Parent-based sleep education for children with autism spectrum disorders.

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and 1 month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group versus individualized education did not affect outcome.

The behavioral phenotype in MECP2 duplication syndrome: a comparison with idiopathic autism.

Alterations in the X-linked gene MECP2 encoding the methyl-CpG-binding protein 2 have been linked to autism spectrum disorders (ASDs). Most recently, data suggest that overexpression of MECP2 may be related to ASD. To better characterize the relevance of MECP2 overexpression to ASD-related behaviors, we compared the core symptoms of ASD in MECP2 duplication syndrome to nonverbal mental age-matched boys with idiopathic ASD. Within the MECP2 duplication group, we further delineated aspects of the behavioral phenotype and also examined how duplication size and gene content corresponded to clinical severity. We compared ten males with MECP2 duplication syndrome (ages 3-10) with a chronological and mental age-matched sample of nine nonverbal males with idiopathic ASD. Our results indicate that boys with MECP2 duplication syndrome share the core behavioral features of ASD (e.g. social affect, restricted/repetitive behaviors). Direct comparisons of ASD profiles revealed that a majority of boys with MECP2 duplication syndrome are similar to idiopathic ASD; they have impairments in social affect (albeit to a lesser degree than idiopathic ASD) and similar severity in restricted/repetitive behaviors. Nonverbal mental age did not correlate with severity of social impairment or repetitive behaviors. Within the MECP2 duplication group, breakpoint size does not predict differences in clinical severity. In addition to social withdrawal and stereotyped behaviors, we also found that hyposensitivity to pain/temperature are part of the behavioral phenotype of MECP2 duplication syndrome. Our results illustrate that overexpression/increased dosage of MECP2 is related to core features of ASD.

Characteristics and predictive value of blood transcriptome signature in males with autism spectrum disorders.

Autism Spectrum Disorders (ASD) is a spectrum of highly heritable neurodevelopmental disorders in which known mutations contribute to disease risk in 20% of cases. Here, we report the results of the largest blood transcriptome study to date that aims to identify differences in 170 ASD cases and 115 age/sex-matched controls and to evaluate the utility of gene expression profiling as a tool to aid in the diagnosis of ASD. The differentially expressed genes were enriched for the neurotrophin signaling, long-term potentiation/depression, and notch signaling pathways. We developed a 55-gene prediction model, using a cross-validation strategy, on a sample cohort of 66 male ASD cases and 33 age-matched male controls (P1). Subsequently, 104 ASD cases and 82 controls were recruited and used as a validation set (P2). This 55-gene expression signature achieved 68% classification accuracy with the validation cohort (area under the receiver operating characteristic curve (AUC): 0.70 [95% confidence interval [CI]: 0.62-0.77]). Not surprisingly, our prediction model that was built and trained with male samples performed well for males (AUC 0.73, 95% CI 0.65-0.82), but not for female samples (AUC 0.51, 95% CI 0.36-0.67). The 55-gene signature also performed robustly when the prediction model was trained with P2 male samples to classify P1 samples (AUC 0.69, 95% CI 0.58-0.80). Our result suggests that the use of blood expression profiling for ASD detection may be feasible. Further study is required to determine the age at which such a test should be deployed, and what genetic characteristics of ASD can be identified.

A multisite study of the clinical diagnosis of different autism spectrum disorders.

CONTEXT: Best-estimate clinical diagnoses of specific autism spectrum disorders (autistic disorder, pervasive developmental disorder-not otherwise specified, and Asperger syndrome) have been used as the diagnostic gold standard, even when information from standardized instruments is available. OBJECTIVE: To determine whether the relationships between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders vary across 12 university-based sites. DESIGN: Multisite observational study collecting clinical phenotype data (diagnostic, developmental, and demographic) for genetic research. Classification trees were used to identify characteristics that predicted diagnosis across and within sites. SETTING: Participants were recruited through 12 university-based autism service providers into a genetic study of autism. PARTICIPANTS: A total of 2102 probands (1814 male probands) between 4 and 18 years of age (mean [SD] age, 8.93 [3.5] years) who met autism spectrum criteria on the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule and who had a clinical diagnosis of an autism spectrum disorder. MAIN OUTCOME MEASURE: Best-estimate clinical diagnoses predicted by standardized scores from diagnostic, cognitive, and behavioral measures. RESULTS: Although distributions of scores on standardized measures were similar across sites, significant site differences emerged in best-estimate clinical diagnoses of specific autism spectrum disorders. Relationships between clinical diagnoses and standardized scores, particularly verbal IQ, language level, and core diagnostic features, varied across sites in weighting of information and cutoffs. CONCLUSIONS: Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments. Results support the move from existing subgroupings of autism spectrum disorders to dimensional descriptions of core features of social affect and fixated, repetitive behaviors, together with characteristics such as language level and cognitive function.

A pilot study to improve venipuncture compliance in children and adolescents with autism spectrum disorders.

OBJECTIVE: Medical procedures, particularly venipuncture (the puncture of a vein especially for the withdrawal of blood), can cause serious distress and behavior disturbance for many children. Noncompliance to blood draws can have significant ramifications in both research and clinical settings. The negative reactions may be exacerbated in individuals with autism spectrum disorders. Even so, there has been little research into the prevalence of the problem or effective intervention procedures. In response to these concerns, we developed and evaluated the Blood Draw Intervention Program. The program was designed to be easy to use, require little provider or family time, effectively reduce negative behaviors, and increase blood draw compliance. METHOD: In a quasi-randomized trial over the course of ∼ 18 months, 58 of 210 families with children with autism spectrum disorders participating in a larger study of phenotypic and genotypic factors reported significant concerns about blood draws and elected to use the Blood Draw Intervention Program. RESULTS: Completion of the program increased blood draw compliance rates from 85.4% to 96.6% (odds ratio = 4.80; 95% confidence interval = 1.12, 20.59; p = .03). CONCLUSION: Results indicate the efficacy of the program in a research setting and suggest a potential clinical application. The current intervention, unlike many others for the same or similar difficulties proposed in the past, was successful without requiring extensive time, training, or effort on the part of providers and parents or their children, nor did it require large-scale institutional changes.

Cognitive and behavioral characterization of 16p11.2 deletion syndrome.

OBJECTIVE: To describe cognitive and behavioral features of patients with chromosome 16p11.2 deletion syndrome, a recently identified and common genetic cause of neurodevelopmental disability, especially autism spectrum disorder (ASD). METHOD: Twenty-one patients with 16p11.2 deletion were evaluated by medical record review. A subset of 11 patients consented to detailed cognitive, behavioral, and autism diagnostic assessment. RESULTS: Patients with 16p11.2 deletion had varying levels of intellectual disability, variable adaptive skills, and a high incidence of language delay. Attention issues were not as frequent as had been reported in previous clinical reports. Atypical language, reduced social skills, and maladaptive behaviors were common, as was diagnosis of ASD. Based on medical record review, 7 of 21 patients (33%) had an ASD diagnosis. Among patients receiving detailed phenotyping, 3 of 11 (27%) met full criteria (met cutoff scores on both Autism Diagnostic Observation Schedule and Autism Diagnostic Interview) for an ASD diagnosis, whereas 6 other patients (55%) met criteria for ASD on either the Autism Diagnostic Observation Schedule or the Autism Diagnostic Interview, but not both measures. CONCLUSIONS: Rates of ASD were similar to previous reports that are based on medical record reviews, but formal assessment revealed that a majority of patients with 16p11.2 deletion demonstrate features of ASD beyond simple language impairment. All patients with 16p11.2 deletion should receive formal neurodevelopmental evaluation including measures to specifically assess cognitive, adaptive, language, and psychiatric/behavioral issues. Clinical evaluation of this patient population should always include assessment by Autism Diagnostic Interview and Autism Diagnostic Observation Schedule to detect behaviors related to ASD and possible ASD diagnosis.