J. Kiely Law

Characteristics and concordance of autism spectrum disorders among 277 twin pairs

OBJECTIVESnTo examine patterns of autism spectrum disorder (ASD) inheritance and other features in twin pairs by zygosity, sex, and specific ASD diagnosis.nnnDESIGNnCross-sectional study.nnnSETTINGnInternet-based autism registry for US residents.nnnPARTICIPANTSnSurvey results from 277 twin pairs (210 dizygotic [DZ] and 67 monozygotic [MZ]) aged 18 years or younger with at least 1 affected twin.nnnMAIN EXPOSURESnZygosity and sex.nnnOUTCOME MEASURESnConcordance within twin pairs of diagnosis, natural history, and results from standardized autism screening.nnnRESULTSnPairwise ASD concordance was 31% for DZ and 88% for MZ twins. Female and male MZ twins were 100% and 86% concordant, respectively, and DZ twin pairs with at least 1 female were less likely to be concordant (20%) than were male-male DZ twin pairs (40%). The hazard ratio for ASD diagnosis of the second twin after a first-twin diagnosis was 7.48 for MZ vs DZ twins (95% confidence interval, 3.8-14.7). Affected DZ individual twins had an earlier age at first parental concern and more frequent diagnoses of intellectual disability than did MZ twins; MZ twins had a higher prevalence of bipolar disorder and Asperger syndrome and higher concordance of the latter. Results of autism screening correlated with parent-reported ASD status in more than 90% of cases.nnnCONCLUSIONSnOur data support greater ASD concordance in MZ vs DZ twins. Overall higher functioning, psychiatric comorbidity, and Asperger syndrome concordance among affected MZ vs DZ twins may also suggest differential heritability for different ASDs. For families in which one MZ twin is diagnosed with ASD, the second twin is unlikely to receive an ASD diagnosis after 12 months. In addition, Internet parent report of ASD status is valid.

Verification of Parent-Report of Child Autism Spectrum Disorder Diagnosis to a Web-Based Autism Registry

Growing interest in autism spectrum disorder (ASD) research requires increasingly large samples to uncover epidemiologic trends; such a large dataset is available in a national, web-based autism registry, the Interactive Autism Network (IAN). The objective of this study was to verify parent-report of professional ASD diagnosis to the registry’s database via a medical record review on a sample of IAN Research participants. Sixty-one percent of families agreed to participate; 98% (nxa0=xa0116) of whom provided documentation verifying a professionally diagnosed ASD. Results of this study suggest that information collected from parents participating in IAN Research is valid, participants can be authenticated, and that scientists can both confidently use IAN data and recruit participants for autism research.

Psychotropic Medication Use Among Children With Autism Spectrum Disorders Enrolled in a National Registry, 2007–2008

Patterns of current psychotropic medication use among 5,181 children with autism spectrum disorders (ASD) enrolled in a Web-based registry were examined. Overall, 35% used at least one psychotropic medication, most commonly stimulants, neuroleptics, and/or antidepressants. Those who were uninsured or exclusively privately insured were less likely to use ≥3 medications than were those insured by Medicaid. Psychiatrists and neurologists prescribed the majority of psychotropic medications. In multivariate analysis, older age, presence of intellectual disability or psychiatric comorbidity, and residing in a poorer county or in the South or Midwest regions of the United States increased the odds of psychotropic medication use. Factors external to clinical presentation likely affect odds of psychotropic medication use among children with ASD.

Trends in Autism Spectrum Disorder Diagnoses: 1994-2007.

We analyzed predictors of parent-reported initial diagnosis (autistic disorder [AD], pervasive developmental disorder-not otherwise specified [PDD-NOS], pervasive developmental disorder [‘PDD’] and autism spectrum disorder [‘ASD’], and Asperger syndrome [AS]), among 6,176 individuals with autism spectrum disorders diagnosed from 1994 through 2007. Overall, distribution of diagnoses was influenced by a secular time trend factor; other significant factors included ethnicity, white race, geographic location, urbanicity, and initial evaluator. Since 2001, most initial diagnoses of AD and AS have remained steady while ‘PDD’ and PDD-NOS have decreased. ‘ASD’ diagnoses have increased, especially among school-based teams; AS diagnoses also increased uniquely among these evaluators. Findings from this study suggest that current diagnostic guidelines may not be meeting all community evaluator needs.

Accuracy of Phenotyping of Autistic Children Based on Internet Implemented Parent Report

While strong familial evidence supports a substantial genetic contribution to the etiology of autism spectrum disorders (ASD), specific genetic abnormalities have been identified in only a small minority of all cases. In order to comprehensively delineate the genetic components of autism including the identification of rare and common variants, overall sample sizes an order of magnitude larger than those currently under study are critically needed. This will require rapid and scalable subject assessment paradigms that obviate clinic‐based time‐intensive behavioral phenotyping, which is a rate‐limiting step. Here, we test the accuracy of a web‐based approach to autism phenotyping implemented within the Interactive Autism Network (IAN). Families who were registered with the IAN and resided near one of the three study sites were eligible for the study. One hundred seven children ascertained from this pool who were verbal, age 4–17 years, and had Social Communication Questionnaire (SCQ) scores ≥12 (a profile that characterizes a majority of ASD‐affected children in IAN) underwent a clinical confirmation battery. One hundred five of the 107 children were ASD positive (98%) by clinicians best estimate. One hundred four of these individuals (99%) were ASD positive by developmental history using the Autism Diagnostic Interview‐Revised (ADI‐R) and 97 (93%) were positive for ASD by developmental history and direct observational assessment (Autism Diagnostic Observational Schedule or expert clinician observation). These data support the reliability and feasibility of the IAN‐implemented parent‐report paradigms for the ascertainment of clinical ASD for large‐scale genetic research.

Occurrence and Family Impact of Elopement in Children With Autism Spectrum Disorders

OBJECTIVES: Anecdotal reports suggest that elopement behavior in children with autism spectrum disorders (ASDs) increases risk of injury or death and places a major burden on families. This study assessed parent-reported elopement occurrence and associated factors among children with ASDs. METHODS: Information on elopement frequency, associated characteristics, and consequences was collected via an online questionnaire. The study sample included 1218 children with ASD and 1076 of their siblings without ASD. The association among family sociodemographic and child clinical characteristics and time to first elopement was estimated by using a Cox proportional hazards model. RESULTS: Forty-nine percent (n = 598) of survey respondents reported their child with an ASD had attempted to elope at least once after age 4 years; 26% (n = 316) were missing long enough to cause concern. Of those who went missing, 24% were in danger of drowning and 65% were in danger of traffic injury. Elopement risk was associated with autism severity, increasing, on average, 9% for every 10-point increase in Social Responsiveness Scale T score (relative risk 1.09, 95% confidence interval: 1.02, 1.16). Unaffected siblings had significantly lower rates of elopement across all ages compared with children with ASD. CONCLUSIONS: Nearly half of children with ASD were reported to engage in elopement behavior, with a substantial number at risk for bodily harm. These results highlight the urgent need to develop interventions to reduce the risk of elopement, to support families coping with this issue, and to train child care professionals, educators, and first responders who are often involved when elopements occur.

Stability of initial autism spectrum disorder diagnoses in community settings.

The study’s objectives were to assess diagnostic stability of initial autism spectrum disorder (ASD) diagnoses in community settings and identify factors associated with diagnostic instability using data from a national Web-based autism registry. A Cox proportional hazards model was used to assess the relative risk of change in initial ASD diagnosis as a function of demographic characteristics, diagnostic subtype, environmental factors and natural history. Autistic disorder was the most stable initial diagnosis; pervasive developmental disorder—not otherwise specified was the least stable. Additional factors such as diagnosing clinician, region, when in time a child was initially diagnosed, and history of autistic regression also were significantly associated with diagnostic stability in community settings. Findings suggest that the present classification system and other secular factors may be contributing to increasing instability of community-assigned labels of ASD.

Parent Report of Community Psychiatric Comorbid Diagnoses in Autism Spectrum Disorders

We used a national online registry to examine variation in cumulative prevalence of community diagnosis of psychiatric comorbidity in 4343 children with autism spectrum disorders (ASD). Adjusted multivariate logistic regression models compared influence of individual, family, and geographic factors on cumulative prevalence of parent-reported anxiety disorder, depression, bipolar disorder, and attention deficit/hyperactivity disorder or attention deficit disorder. Adjusted odds of community-assigned lifetime psychiatric comorbidity were significantly higher with each additional year of life, with increasing autism severity, and with Asperger syndrome and pervasive developmental disorder—not otherwise specified compared with autistic disorder. Overall, in this largest study of parent-reported community diagnoses of psychiatric comorbidity, gender, autistic regression, autism severity, and type of ASD all emerged as significant factors correlating with cumulative prevalence. These findings could suggest both underlying trends in actual comorbidity as well as variation in community interpretation and application of comorbid diagnoses in ASD.

Factors Affecting Age at Initial Autism Spectrum Disorder Diagnosis in a National Survey

Entry into early intervention depends on both age of first parent concern (AOC) and age at initial autism spectrum disorder (ASD) diagnosis (AOD). Using data collected from a national online registry from 6214 children diagnosed with an ASD between 1994 and 2010 in the US, we analyzed the effect of individual, family, and geographic covariates on AOC and AOD in a multivariate linear regression model with random effects. Overall, no single modifiable factor associated with AOC or AOD emerged but cumulative variation in certain individual- and family-based features, as well as some geographic factors, all contribute to AOC and AOD variation. A multipronged strategy is needed for targeted education and awareness campaigns to maximize outcomes and decrease disparities in ASD care.

The relationship between the medical home and unmet needs for children with autism spectrum disorders

The purpose of this study was to examine the relationship between having access to a medical home and unmet needs for specialty care services for children with autism spectrum disorders (ASD). Parents of children enrolled in a national autism registry were invited to complete an online Access to Care Questionnaire. The resulting sample consisted of 371 parents–child dyads. Bivariate and hierarchical regression analyses were conducted to determine whether having a medical home was associated with the number of unmet needs for specialty care. Less than one in five children with ASD had a medical home (18.9xa0%). Nearly all parents reported that their child had a personal doctor or nurse as well as a usual source of care, but less than one-third received coordinated care (29.9xa0%) and less than one-half received family-centered care (47.1xa0%). Many children had unmet needs (63xa0%), and the highest unmet need was for behavioral therapy. Having a medical home was associated with fewer unmet specialty care needs, even after demographic, child and family characteristics were taken into account. Children with ASD who have a medical home are more likely to have adequate access to needed services. Unfortunately, relatively few children have a medical home that includes family-centered and coordinated care. Enhancements in the delivery of primary care for children with ASD may make a real difference in access to needed specialty care services, potentially improving child and family outcomes.