ABSTRACT
The Modified Checklist for Autism in Toddlers (M-CHAT) was used to screen younger (16-23 months) versus older (24-30 months) high- and low-risk toddlers. Refusal rates for follow-up interview showed no group differences, but parents of younger/low-risk children were more likely to refuse evaluation than parents of high-risk children. PPP for an ASD diagnosis was: younger/high-risk 0.79, older/high-risk 0.74, younger/low-risk 0.28, and older/low-risk 0.61, with PPP differing by age within the low-risk group. Most of the children in all groups, however, were diagnosed with a developmental disorder. Symptom severity generally did not differ among groups. Cognitive and adaptive measures showed minimal group differences. Therefore, older and younger toddlers had similar symptomatology and developmental delays; PPP for ASD is better at 24 than 18 months for low-risk children; however, these children are still highly likely to show a developmental disorder. Clinical decision making should balance early identification against the lower specificity of M-CHAT screening for the younger/low-risk group.
Subject(s)
Autistic Disorder/diagnosis , Autistic Disorder/epidemiology , Mass Screening/methods , Surveys and Questionnaires , Child, Preschool , Female , Humans , Male , Observer VariationABSTRACT
BACKGROUND: Autism spectrum disorders (ASD) are neurodevelopmental disorders of complex etiology, with a recognized substantial contribution of heterogeneous genetic factors; one of the core features of ASD is a lack of affiliative behaviors. METHODS: On the basis of the existing literature, in this study we examined the hypothesis of allelic associations between genetic variants in six genes involved in control of maternal and affiliative behaviors (OXT, OXTR, PRL, PRLR, DbetaH, and FOSB). One hundred and seventy-seven probands with ASD from 151 families (n = 527) were assessed with a set of related instruments capturing multiple facets of ASD. Multivariate and univariate phenotypes were constructed from these assessments and subjected to genetic linkage and association analyses with PBAT and FBAT software. RESULTS: The resulting pattern of findings, in general, confirmed the hypotheses of the significance of the genes involved in the development of affiliative behaviors in the manifestation of ASD (p values ranging from .000005 to .05); statistically speaking, the strongest results were obtained for allelic associations with the PRL, PRLR, and OXTR genes. CONCLUSIONS: These preliminary data provide additional support for the hypothesis that the allelic variants of genes necessary for the development of species-typical affiliative behaviors are associated with ASD. Independent replication of these findings is needed and studies of other genes associated with affiliative behaviors are indicated.
Subject(s)
Autistic Disorder/genetics , Autistic Disorder/physiopathology , Behavior/physiology , Genetic Linkage , Genetic Predisposition to Disease , Analysis of Variance , Asperger Syndrome/genetics , Child , Dopamine beta-Hydroxylase/genetics , Family Health , Female , Genetic Variation , Genotype , Humans , Male , Organizational Affiliation , Oxytocin/genetics , Prolactin/genetics , Proto-Oncogene Proteins c-fos/genetics , Receptors, Oxytocin/genetics , Receptors, Prolactin/geneticsABSTRACT
This study compared behavioral presentation of toddlers with autistic spectrum disorders (ASD) and toddlers with global developmental delay (DD) or developmental language disorder (DLD) who display some characteristics of ASD using the diagnostic algorithm items from the Autism Diagnostic Observation Schedule, Generic (ADOS), the Childhood Autism Rating Scale (CARS), and Modified Checklist for Autism in Toddlers (M-CHAT). To date, 195 children have failed the M-CHAT and have been diagnosed with ASD, DD or DLD. Children with ASD had prominent and consistent impairments in socialization skills, especially joint attention skills and were more impaired in some aspects of communication, play, and sensory processing. Children with ASD and children with DD/DLD shared common features, but certain behavioral markers differentiated the two groups.
Subject(s)
Autistic Disorder/diagnosis , Developmental Disabilities/diagnosis , Early Diagnosis , Language Development Disorders/diagnosis , Mass Screening , Child, Preschool , Diagnosis, Differential , Female , Humans , Infant , MaleABSTRACT
We compared the reading-related skills of children with Autism Spectrum Disorders who have hyperlexia (ASD + HPL) with age-matched children with ASD without HPL (ASD - HPL) and with single-word reading-matched typically developing children (TYP). Children with ASD + HPL performed (1) better than did children with ASD - HPL on tasks of single-word reading and pseudoword decoding and (2) equivalently well compared to word-reading-matched TYP children on all reading-related tasks except reading comprehension. It appears that the general underlying model of single-word reading is the same in principle for "typical" and hyperlexic reading. Yet, the study revealed some dissimilarities between these two types of reading when more fine-grained cognitive and linguistic abilities were considered; these dissimilarities warrant further investigations.
