A comparison of central coherence skills between adolescents with an intellectual disability with and without comorbid autism spectrum disorder

Central coherence theory hypothesizes individuals with autism process information in a detail-focused fashion. The present study examined whether adolescents with an intellectual disability and comorbid autism spectrum disorder showed a weaker central coherence than age- and IQ-matched controls. The central coherence skills of 43 adolescents from schools for students with severe learning problems were examined with two cognitive tasks. In these two tasks, detail-focused processing is beneficial to global processing to perform the tasks accurately and quickly. The group with autism spectrum disorder performed better than the control group. Adolescents with an intellectual disability and with comorbid autism spectrum disorder have a weaker central coherence than age- and IQ-matched controls. Partial support was also given for variability in weak central coherence within the autism spectrum. (c) 2005 Elsevier Ltd. All rights reserved

Structural equation analysis of a hypothesised symptom model in the autism spectrum

Background: Several studies showed a different symptom structure underlying the spectrum of autistic-like disorders from the behaviour triad as mentioned in the DSM-IV. In the present study, a hypothesised symptom model for autism was constructed, based on earlier explorative findings, and was put to a confirmatory test. Method: Items from the Autism Diagnostic Interview-Revised (ADI-R) were used to examine the goodness of fit of the DSM-IV model, the hypothesised symptom model, and two additional models for autism. All models were tested in a group of 255 verbal and nonverbal individuals with minor to severe autistic symptomatology. Results: The DSM-IV model encountered estimation problems. Conversely, the hypothesised symptom model had no such problems and proved to have a better fit to the sample data than the two additional models for autism. However, some of the observed variables were weak indicators of the three latent factors in the model. Conclusions: The hypothesised symptom model appeared to be a plausible model in a group of individuals with a broad range of autistic behaviours and levels of functioning. Nevertheless, the stability of the model needs further examination in a larger group of individuals with disorders in the autism spectrum, and with varying degrees of intellectual functioning.

The psychiatric phenotype in triple X syndrome: New hypotheses illustrated in two cases

Item does not contain fulltextBackground: Triple X syndrome (47, XXX or trisomy X) is a relatively frequent cytogenetic condition with a large variety of physical and behavioural phenotypes. Method: Two adult patients with a triple X karyotype are described. Results: Their karyotype was unknown until some years ago. What these patients have in common is that they were diagnosed with a broader autism phenotype, they were sexually abused, they suffer from psychotic illness and they show challenging behaviour, suicidality and a decline in occupational capacity. Discussion: These gene-environment interactions are discussed. Gene-environment interactions may explain the variety of behavioural and psychiatric phenotypes in triple X syndrome. Ongoing atypical development in adults is hypothesized. Conclusions: Gene-environment interactions and ongoing atypical development in adults should be taken into account in research concerning the psychiatric phenotype of developmental disorders, especially those involving triple X syndrome.6 p

A 3-base pair deletion, c.9711_9713del, in DMD results in intellectual disability without muscular dystrophy

We have identified a deletion of 3 base pairs in the dystrophin gene (DMD), c.9711_9713del, in a family with nonspecific X-linked intellectual disability (ID) by sequencing of the exons of 86 known X-linked ID genes. This in-frame deletion results in the deletion of a single-amino-acid residue, Leu3238, in the brain-specific isoform Dp71 of dystrophin. Linkage analysis supported causality as the mutation was present in the 7.6 cM linkage interval on Xp22.11-Xp21.1 with a maximum positive LOD score of 2.41 (MRX85 locus). Molecular modeling predicts that the p.(Leu3238del) deletion results in the destabilization of the C-terminal domain of dystrophin and hence reduces the ability to interact with beta-dystroglycan. Correspondingly, Dp71 protein levels in lymphoblastoid cells from the index patient are 6.7-fold lower than those in control cell lines (P=0.08). Subsequent determination of the creatine kinase levels in blood of the index patient showed a mild but significant elevation in serum creatine kinase, which is in line with impaired dystrophin function. In conclusion, we have identified the first DMD mutation in Dp71 that results in ID without muscular dystrophy

Emotional Development in Adults with Autism and Intellectual Disabilities: A Retrospective, Clinical Analysis

Individuals with intellectual disability (ID) are at risk for additional autism spectrum disorders (ASD). A large amount of research reveals deficits in emotion-related processes that are relevant to social cognition in ASD. However, studies on the structure and level of emotional development (ED) assessing emotional maturity according to the normative trajectory in typically developing children are scares. The level of ED can be evaluated by the 'Scheme of Appraisal of Emotional Development' (SAED), a semi-structured interview with a close caregiver. The SAED assesses the level of emotional developmental based on a five stage system in 10 domains, for example, 'interaction with peers' or 'object permanence', which are conducive to the overall emotional developmental level. This study examined the ED as measured by the SAED in 289 adults (mean age: 36 years) with ID with and without additional ASD. A lower level in ED was observed in ASD/ID combined that corresponded to the ED of typically developing children aged 1.5-3 years versus an ED with a corresponding age of 3-7 years in ID individuals without ASD. Moreover, distinct strengths in 'object permanence', and weaknesses in 'interaction', 'verbal communication', 'experience of self', 'affect differentiation', 'anxiety', and 'handling of material objects' led to a characteristic pattern of ED in ASD. SAED domains with highest discriminative power between ID individuals with and without ASD (5/10) were used to predict ASD group membership. The classification using a selection of SAED domains revealed a sensitivity of 77.5% and a specificity of 76.4%. ASD risk increased 2.7-fold with every SAED level. The recognition of delayed and uneven pattern of ED contributes to our understanding of the emotion-related impairments in adults with ID and ASD these individuals. Assessment of intra-individual ED could add value to the standard diagnostic procedures in ID, a population at risk for underdiagnosed ASD. © 2013 Sappok et al