Marian Sigman

A longitudinal study of joint attention and language development in autistic children

This study was designed to examine the degree to which individual differences in gestural joint attention skills predicted language development among autistic children. A group of 15 autistic children (mean CA=45 months) were matched with one group of mentally retarded (MR) children on mental age and another group of MR children on language age. These groups were administered the Early Social-Communication Scales. The latter provided measures of gestural requesting, joint attention, and social behaviors. The results indicated that, even when controlling for language level, mental age, or IQ, autistic children displayed deficits in gestural joint attention skills on two testing sessions that were 13 months apart. Furthermore, the measure of gestural nonverbal joint attention was a significant predictor of language development in the autistic sample. Other variables, including initial language level and IQ were not significant predictors of language development in this sample.

Common genetic variants on 5p14.1 associate with autism spectrum disorders

Autism spectrum disorders (ASDs) represent a group of childhood neurodevelopmental and neuropsychiatric disorders characterized by deficits in verbal communication, impairment of social interaction, and restricted and repetitive patterns of interests and behaviour. To identify common genetic risk factors underlying ASDs, here we present the results of genome-wide association studies on a cohort of 780 families (3,101 subjects) with affected children, and a second cohort of 1,204 affected subjects and 6,491 control subjects, all of whom were of European ancestry. Six single nucleotide polymorphisms between cadherin 10 (CDH10) and cadherin 9 (CDH9)—two genes encoding neuronal cell-adhesion molecules—revealed strong association signals, with the most significant SNP being rs4307059 (P = 3.4 × 10-8, odds ratio = 1.19). These signals were replicated in two independent cohorts, with combined P values ranging from 7.4 × 10-8 to 2.1 × 10-10. Our results implicate neuronal cell-adhesion molecules in the pathogenesis of ASDs, and represent, to our knowledge, the first demonstration of genome-wide significant association of common variants with susceptibility to ASDs.

Parenting and childhood anxiety: theory, empirical findings, and future directions

Theories of anxiety development suggest that parental acceptance, control, and modeling of anxious behaviors are associated with childrens manifestations of anxiety. This paper reviews research published in the past decade on the relation between parenting and childhood anxiety. Observed parental control during parent-child interactions was consistently linked with shyness and child anxiety disorders across studies. Mixed support for the role of parental acceptance and modeling of anxious behaviors was found in observational studies. However, there was little evidence supporting the contention that self-reported parenting style was related to childrens trait anxiety. Because of limitations associated with past research, inferences about the direction of effects linking parenting and child anxiety cannot be made. A conceptual framework based on recent models of anxiety development (e.g., Vasey & Dadds, 2001) is presented to aid in the interpretation of extant research findings and to provide suggestions for future research and theory development. Improved methodological designs are proposed, including the use of repeated-measure and experimental designs for examining the direction of effects.

Recurrence risk for autism spectrum disorders: A baby siblings research consortium study

OBJECTIVE: The recurrence risk of autism spectrum disorders (ASD) is estimated to be between 3% and 10%, but previous research was limited by small sample sizes and biases related to ascertainment, reporting, and stoppage factors. This study used prospective methods to obtain an updated estimate of sibling recurrence risk for ASD. METHODS: A prospective longitudinal study of infants at risk for ASD was conducted by a multisite international network, the Baby Siblings Research Consortium. Infants (n = 664) with an older biological sibling with ASD were followed from early in life to 36 months, when they were classified as having or not having ASD. An ASD classification required surpassing the cutoff of the Autism Diagnostic Observation Schedule and receiving a clinical diagnosis from an expert clinician. RESULTS: A total of 18.7% of the infants developed ASD. Infant gender and the presence of >1 older affected sibling were significant predictors of ASD outcome, and there was an almost threefold increase in risk for male subjects and an additional twofold increase in risk if there was >1 older affected sibling. The age of the infant at study enrollment, the gender and functioning level of the infants older sibling, and other demographic factors did not predict ASD outcome. CONCLUSIONS: The sibling recurrence rate of ASD is higher than suggested by previous estimates. The size of the current sample and prospective nature of data collection minimized many limitations of previous studies of sibling recurrence. Clinical implications, including genetic counseling, are discussed.

The behaviors of parents of children with autism predict the subsequent development of their children's communication.

The present study focused on behaviors that caregivers of children with autism show during play interactions, particularly the extent to which the caregivers behavior is synchronized with the childs focus of attention and ongoing activity. The study had two major findings. First, caregivers of children with autism synchronized their behaviors to their childrens attention and activities as much as did caregivers of children with developmental delay and caregivers of typically developing children, matched on language capacities. Second, caregivers of children with autism who showed higher levels of synchronization during initial play interactions had children who developed superior joint attention and language over a period of 1, 10, and 16 years than did children of caregivers who showed lower levels of synchronization initially. These findings suggest a developmental link between parental sensitivity and the childs subsequent development of communication skills in children with autism. Implications for parent training interventions are discussed.

Characterizing interactions between anxious mothers and their children.

The present study assessed interactions between anxious mothers and their children, using observational techniques to elucidate potential mechanisms of anxiety transmission. Results revealed that anxious mothers were less warm and positive in their interactions with their children, less granting of autonomy, and more critical and catastrophizing in comparison with normal control mothers. Maternal anxiety status appeared to be the primary predictor of maternal warmth during interactions. Child anxiety status was most predictive of maternal granting of autonomy behavior. Maternal behaviors exhibited during interactions were the most salient predictors of child anxiety, contributing more than maternal psychopathology or ongoing strain to the development of child anxiety. Interventions focusing on family interactions that take into account the contributions of both members of the dyad may be more effective in curbing transmission than interventions that solely address maternal or child symptomatology.

Affective sharing in the context of joint attention interactions of normal, autistic, and mentally retarded children

Disturbances in the development of joint attention behaviors and the ability to share affect with others are two important components of the social deficits of young autistic children. We examined the association of shared positive affect during two different communicative contexts, joint attention and requesting. The pattern for the normal children was one of frequent positive affect displayed toward the adult during joint attention situations. Compared to the normal children, the autistic children failed to display high levels of positive affect during joint attention whereas the mentally retarded children displayed high levels of positive affect during requesting as well as joint attention situations. These results lend support to the hypothesis that the joint attention deficits in autistic children also are associated with a disturbance in affective sharing.

Genome-Wide Analyses of Exonic Copy Number Variants in a Family-Based Study Point to Novel Autism Susceptibility Genes

The genetics underlying the autism spectrum disorders (ASDs) is complex and remains poorly understood. Previous work has demonstrated an important role for structural variation in a subset of cases, but has lacked the resolution necessary to move beyond detection of large regions of potential interest to identification of individual genes. To pinpoint genes likely to contribute to ASD etiology, we performed high density genotyping in 912 multiplex families from the Autism Genetics Resource Exchange (AGRE) collection and contrasted results to those obtained for 1,488 healthy controls. Through prioritization of exonic deletions (eDels), exonic duplications (eDups), and whole gene duplication events (gDups), we identified more than 150 loci harboring rare variants in multiple unrelated probands, but no controls. Importantly, 27 of these were confirmed on examination of an independent replication cohort comprised of 859 cases and an additional 1,051 controls. Rare variants at known loci, including exonic deletions at NRXN1 and whole gene duplications encompassing UBE3A and several other genes in the 15q11–q13 region, were observed in the course of these analyses. Strong support was likewise observed for previously unreported genes such as BZRAP1, an adaptor molecule known to regulate synaptic transmission, with eDels or eDups observed in twelve unrelated cases but no controls (p = 2.3×10−5). Less is known about MDGA2, likewise observed to be case-specific (p = 1.3×10−4). But, it is notable that the encoded protein shows an unexpectedly high similarity to Contactin 4 (BLAST E-value = 3×10−39), which has also been linked to disease. That hundreds of distinct rare variants were each seen only once further highlights complexity in the ASDs and points to the continued need for larger cohorts.

Cognitive and Language Skills in Autistic, Mentally Retarded, and Normal Children.

Compared the sensorimotor skills and play behaviors of 16 normal 16-25 mo old children, 16 mentally retarded children (CA 32-80 mo, MA 17-38 mo), and 16 autistic children (CA 39-74 mo, MA 18-38 mo) to identify deficits in object knowledge specific to autism. There were no differences in sensorimotor

Symbolic Play and Language Comprehension in Autistic Children

Abstract The objectives of this study were to examine the play of young autistic children and to determine the relationship between play and language comprehension in this group. Structured and free play assessments and a test of receptive language were administered to a sample of 16 autistic children with a mean mental age of 24.8 months. The autistic children demonstrated a wide range of different play behaviors, but their play was different from the play observed in normal children of comparable mental age. They distributed their play time differently from normals by spending equal amounts of time in immature and mature forms of play. In addition, they directed less play activity toward dolls. Autistic children with high language comprehension demonstrated more functional and symbolic play and longer sequences of meaningfully integrated play acts than autistic children with low language comprehension. The results indicated that deviance in the early symbolic development of autistic children is manifest in their functional use of objects in play. Impairments in play were related to language comprehension, supporting the notion of a generalized symbolic impairment in autistic children.