A preliminary study of screening for risk of autism in children with fragile X syndrome: testing two risk cut-offs for the Checklist for Autism in Toddlers

Early Infant Development and Intervention for Autism Spectrum Disorder

OBJECTIVE

The objective is to overview recent findings on early detection/diagnosis of autism spectrum disorders, as well as clinical trials of early interventions for toddlers at risk for/diagnosed with autism spectrum disorder.

FINDINGS

Prospective studies of infants at high risk of autism spectrum disorder have yielded significant advances in understanding early development in autism spectrum disorder. Findings from prospective studies indicate that abnormalities in social communication and repetitive behaviors emerge during the second year, whereas additional "prodromal features" (motor and sensory abnormalities) emerge in the first year. Subsequently, exciting progress has been made in establishing the efficacy of autism spectrum disorder-specific interventions for toddlers as young as 15 months. Finally, efforts occur to characterize autism spectrum disorder-specific characteristics in genetic syndromes with concurrent autism spectrum disorder symptomatology.

CONCLUSION

Substantial progress in characterizing early developmental trajectories as well as the identification of specific behavioral markers has aided early detection. Work remains to ensure that research findings are translated into clinical practice for uptake in the health care system.

Evaluation of the GABAergic nervous system in autistic brain: (123)I-iomazenil SPECT study

PURPOSE

To evaluate the GABA(A) receptor in the autistic brain, we performed (123)I-IMZ SPECT in patients with ASD. We compared (123)I-IMZ SPECT abnormalities in patients who showed intellectual disturbance or focal epileptic discharge on EEG to those in patients without such findings.

SUBJECTS AND METHODS

The subjects consisted of 24 patients with ASD (mean age, 7.3±3.5 years), including 9 with autistic disorder (mean age, 7.0±3.7 years) and 15 with Asperger's disorder (mean age, 7.5±3.2 years). We used 10 non-symptomatic partial epilepsy patients (mean age, 7.8±3.6 years) without intellectual delay as a control group. For an objective evaluation of the (123)I-IMZ SPECT results, we performed an SEE (Stereotactic Extraction Estimation) analysis to describe the decrease in accumulation in each brain lobule numerically.

RESULTS

In the comparison of the ASD group and the control group, there was a dramatic decrease in the accumulation of (123)I-IMZ in the superior and medial frontal cortex. In the group with intellectual impairment and focal epileptic discharge on EEG, the decrease in accumulation in the superior and medial frontal cortex was greater than that in the group without these findings.

CONCLUSION

The present results suggest that disturbance of the GABAergic nervous system may contribute to the pathophysiology and aggravation of ASD, since the accumulation of (123)I-IMZ was decreased in the superior and medial frontal cortex, which is considered to be associated with inference of the thoughts, feelings, and intentions of others (Theory of Mind).

Distinguishing features of autism in boys with fragile X syndrome

BACKGROUND

Males with fragile X syndrome and autism (FXS/autism) represent a distinct subgroup of males with FXS at risk for markedly poorer outcomes. Early identification and intervention can improve outcomes for males with autism spectrum disorder.

METHOD

To advance the development of a specialised autism screening tool for young males with FXS that could assist in early identification, backward regression was used to identify the combination of parent-report questionnaire items that best predicted autism symptoms in a sample of 60 males with FXS, ages 4-18 years old.

RESULTS

Both social and repetitive behaviours distinguished males with FXS/autism, with repetitive behaviours playing a more prominent role than previously documented in the literature.

CONCLUSIONS

Healthcare workers and early interventionists may be able to interview parents about a few key behaviours to determine if young child with FXS should be formally evaluated for autism. Evidence-based practices identified for children with autism spectrum disorder can be implemented as early as possible.