Dataset Information

A prospective study of the emergence of early behavioral signs of autism.

ABSTRACT:

Objective

To examine prospectively the emergence of behavioral signs of autism in the first years of life in infants at low and high risk for autism.

Method

A prospective longitudinal design was used to compare 25 infants later diagnosed with an autism spectrum disorder (ASD) with 25 gender-matched low-risk children later determined to have typical development. Participants were evaluated at 6, 12, 18, 24, and 36 months of age. Frequencies of gaze to faces, social smiles, and directed vocalizations were coded from video and rated by examiners.

Results

The frequency of gaze to faces, shared smiles, and vocalizations to others were highly comparable between groups at 6 months of age, but significantly declining trajectories over time were apparent in the group later diagnosed with ASD. Group differences were significant by 12 months of age on most variables. Although repeated evaluation documented loss of skills in most infants with ASD, most parents did not report a regression in their child's development.

Conclusions

These results suggest that behavioral signs of autism are not present at birth, as once suggested by Kanner, but emerge over time through a process of diminishment of key social communication behaviors. More children may present with a regressive course than previously thought, but parent report methods do not capture this phenomenon well. Implications for onset classification systems and clinical screening are also discussed.

SUBMITTER: Ozonoff S

PROVIDER: S-EPMC2923050 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature

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Publications

A prospective study of the emergence of early behavioral signs of autism.

Ozonoff Sally S Iosif Ana-Maria AM Baguio Fam F Cook Ian C IC Hill Monique Moore MM Hutman Ted T Rogers Sally J SJ Rozga Agata A Sangha Sarabjit S Sigman Marian M Steinfeld Mary Beth MB Young Gregory S GS

Journal of the American Academy of Child and Adolescent Psychiatry 20100301 3

<h4>Objective</h4>To examine prospectively the emergence of behavioral signs of autism in the first years of life in infants at low and high risk for autism.<h4>Method</h4>A prospective longitudinal design was used to compare 25 infants later diagnosed with an autism spectrum disorder (ASD) with 25 gender-matched low-risk children later determined to have typical development. Participants were evaluated at 6, 12, 18, 24, and 36 months of age. Frequencies of gaze to faces, social smiles, and dire ...[more]

PMID: 20410715

Similar Datasets

Project description:BackgroundEpigenetic mechanisms such as altered DNA methylation have been suggested to play a role in autism, beginning with the classical association of Prader-Willi syndrome, an imprinting disorder, with autistic features.ObjectivesHere we tested for the relationship of paternal sperm DNA methylation with autism risk in offspring, examining an enriched-risk cohort of fathers of autistic children.MethodsWe examined genome-wide DNA methylation (DNAm) in paternal semen biosamples obtained from an autism spectrum disorder (ASD) enriched-risk pregnancy cohort, the Early Autism Risk Longitudinal Investigation (EARLI) cohort, to estimate associations between sperm DNAm and prospective ASD development, using a 12-month ASD symptoms assessment, the Autism Observation Scale for Infants (AOSI). We analysed methylation data from 44 sperm samples run on the CHARM 3.0 array, which contains over 4 million probes (over 7 million CpG sites), including 30 samples also run on the Illumina Infinium HumanMethylation450 (450K) BeadChip platform (∼485 000 CpG sites). We also examined associated regions in an independent sample of post-mortem human brain ASD and control samples for which Illumina 450K DNA methylation data were available.ResultsUsing region-based statistical approaches, we identified 193 differentially methylated regions (DMRs) in paternal sperm with a family-wise empirical P-value [family-wise error rate (FWER)] <0.05 associated with performance on the Autism Observational Scale for Infants (AOSI) at 12 months of age in offspring. The DMRs clustered near genes involved in developmental processes, including many genes in the SNORD family, within the Prader-Willi syndrome gene cluster. These results were consistent among the 75 probes on the Illumina 450K array that cover AOSI-associated DMRs from CHARM. Further, 18 of 75 (24%) 450K array probes showed consistent differences in the cerebellums of autistic individuals compared with controls.ConclusionsThese data suggest that epigenetic differences in paternal sperm may contribute to autism risk in offspring, and provide evidence that directionally consistent, potentially related epigenetic mechanisms may be operating in the cerebellum of individuals with autism.

Dataset Information

A prospective study of the emergence of early behavioral signs of autism.

Objective

Method

Results

Conclusions

Publications

A prospective study of the emergence of early behavioral signs of autism.

Similar Datasets

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