Neurophysiological indices of atypical auditory processing and multisensory integration are associated with symptom severity in autism

Atypical processing and integration of sensory inputs are hypothesized to play a role in unusual sensory reactions and social-cognitive deficits in autism spectrum disorder (ASD). Reports on the relationship between objective metrics of sensory processing and clinical symptoms, however, are surprisingly sparse. Here we examined the relationship between neurophysiological assays of sensory processing and (1) autism severity and (2) sensory sensitivities, in individuals with ASD aged 6-17. Multiple linear regression indicated significant associations between neural markers of auditory processing and multisensory integration, and autism severity. No such relationships were apparent for clinical measures of visual/auditory sensitivities. These data support that aberrant early sensory processing contributes to autism symptoms, and reveal the potential of electrophysiology to objectively subtype autism.

Acquired autistic behaviors in children with mucopolysaccharidosis type IIIA

OBJECTIVES

To assess autism spectrum disorder (ASD) behaviors in children with mucopolysaccharidosis type IIIA (MPS IIIA) using a standard measure, understand the behavioral evolution of the disease, and provide specific guidelines for diagnosis.

STUDY DESIGN

Children (n = 21) with documented enzyme deficiency and SGSH gene mutations, cognitive age-equivalent >12 months, and early onset were administered the Autism Diagnostic Observation Schedule (ADOS) (module 1) and Bayley Scales of Infant Development-Third Edition. ADOS Social Affect and Restricted Repetitive Behavior total scores, as well as Bayley Scales of Infant Development-Third Edition cognitive age-equivalent scores, are reported using descriptive statistics and graphic presentations.

RESULTS

Thirteen of the 21 children evaluated met the ADOS criteria for ASD/autism. ADOS score was strongly associated with age; all 11 children aged >46 months met the criteria, compared with only 2 of 10 aged <46 months. Social and affective abnormalities were most frequent; restricted interests and repetitive behaviors were largely absent. Lack of cognitive growth paralleled ADOS score.

CONCLUSION

An increased incidence of ASD-like social behaviors was seen at age 3-4 years in children with early-onset MPS IIIA. Although more frequent in the severely impaired children, ASD-like behaviors were observed across the entire range of cognitive impairment. Clinicians must be aware that when a child acquires ASD-like behaviors, MPS IIIA should be included in the differential diagnosis.

Diagnosing autism spectrum disorders in adults: the use of Autism Diagnostic Observation Schedule (ADOS) module 4

Autism Diagnostic Observation Schedule (ADOS) module 4 was investigated in an independent sample of high-functioning adult males with an autism spectrum disorder (ASD) compared to three specific diagnostic groups: schizophrenia, psychopathy, and typical development. ADOS module 4 proves to be a reliable instrument with good predictive value. It can adequately discriminate ASD from psychopathy and typical development, but is less specific with respect to schizophrenia due to behavioral overlap between autistic and negative symptoms. However, these groups differ on some core items and explorative analyses indicate that a revision of the algorithm in line with Gotham et al. (J Autism Dev Disord 37: 613-627, 2007) could be beneficial for discriminating ASD from schizophrenia.

Association of oxytocin receptor (OXTR) gene variants with multiple phenotype domains of autism spectrum disorder

Autism spectrum disorder (ASD) is characterized by core deficits in social behavior, communication, and behavioral flexibility. Several lines of evidence indicate that oxytocin, signaling through its receptor (OXTR), is important in a wide range of social behaviors. In attempts to determine whether genetic variations in the oxytocin signaling system contribute to ASD susceptibility, seven recent reports indicated association of common genetic polymorphisms in the OXTR gene with ASD. Each involved relatively small sample sizes (57 to 436 families) and, where it was examined, failed to identify association of OXTR polymorphisms with measures of social behavior in individuals with ASD. We report genetic association analysis of 25 markers spanning the OXTR locus in 1,238 pedigrees including 2,333 individuals with ASD. Association of three markers previously implicated in ASD susceptibility, rs2268493 (P = 0.043), rs1042778 (P = 0.037), and rs7632287 (P = 0.016), was observed. Further, these genetic markers were associated with multiple core ASD phenotypes, including social domain dysfunction, measured by standardized instruments used to diagnose and describe ASD. The data suggest association of OXTR genetic polymorphisms with ASD, although the results should be interpreted with caution because none of the significant associations would survive appropriate correction for multiple comparisons. However, the current findings of association in a large independent cohort are consistent with previous results, and the biological plausibility of participation of the oxytocin signaling system in modulating social disruptions characteristic of ASD, suggest that functional polymorphisms of OXTR may contribute to ASD risk in a subset of families.

Overlap with the autism spectrum in young children with Williams syndrome

OBJECTIVE

The sociocommunicative abnormalities of young children with Williams syndrome (WS) with limited language were compared with those of children with clinical diagnoses of autism, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), or nonspectrum developmental disability.

METHOD

Participants were 30 children with WS and individually matched groups of participants with autism (n = 28), PDD-NOS (n = 17), and mixed etiology nonspectrum developmental disabilities (n = 16). The autism, PDD-NOS, and mixed etiology groups were matched individually to the children with WS for age, sex, and developmental level. All participants were administered the Autism Diagnostic Observation Schedule Module 1 and the Mullen Scales of Early Learning.

RESULTS

As a group, children with WS with limited language showed fewer sociocommunicative abnormalities than children with autism, about the same level as children with PDD-NOS, and more abnormalities in reciprocity social interaction than participants in the mixed etiology group. Examination of the subgroup of participants with WS matched and compared with children with PDD-NOS indicated that half of the children showed fewer abnormalities than their individual matches with PDD-NOS, whereas half of the children with WS showed more abnormalities than their matches with PDD-NOS.

CONCLUSION

Sociocommunicative difficulties are present for many children with WS and overlap with the autism spectrum. The results of this investigation suggest that these abnormalities are not accounted for by developmental delay alone, and care should be taken to avoid diagnostic overshadowing in young children with WS.

Autism profiles of males with fragile X syndrome

Autism, which is common in individuals with fragile X syndrome, is often difficult to diagnose. We compared the diagnostic classifications of two measures for autism diagnosis, the ADOS and the ADI-R, in addition to the DSM-IV-TR in 63 males with this syndrome. Overall, 30% of the subjects met criteria for autistic disorder and 30% met criteria for PDD-NOS. The classifications on the ADOS and DSM-IV-TR were most similar, whereas the ADI-R classified subjects as autistic much more frequently. We further investigated the relationship of both FMRP and FMRI mRNA to symptoms of autism in this cohort and found no significant relationship between the measures of autism and molecular features, including FMRP, FMRI mRNA, and CGG repeat number.