Neuropsychological Profile of Italian Children and Adolescents with 22q11.2 Deletion Syndrome with and Without Intellectual Disability

Abstract

As individuals with chromosome 22q11.2 deletion syndrome (22q11DS) show a wide range of IQs, intellectual heterogeneity could mask the neuropsychological profile of the syndrome. This study was designed to identify specific neuropsychological features of children and adolescents with 22q11DS by taking into account the possible source of variability deriving from intellectual disability (ID). First, we compared several neuropsychological domains involving linguistic, visual-motor/visual-perceptual and memory abilities in 34 children and adolescents with 22q11DS and 83 mental age-matched typically developing (TD) participants. Then, we selected participants with 22q11DS according to whether or not they had ID and compared their neuropsychological profiles with those of chronological age-matched TD controls. Although language and several aspects of memory have been found impaired only in children with 22q11DS with ID, deficits in visual-spatial abilities and visual-object short-term memory persist in participants without ID and might be considered a characteristic of 22q11DS, not just related to the presence of ID. On the basis of our findings, children and adolescents with 22q11DS cannot be considered as a single group with a homogeneous neuropsychological profile and must be studied in relation to their global intellectual abilities.

Visual memory profile in 22q11.2 microdeletion syndrome: are there differences in performance and neurobiological substrates between tasks linked to ventral and dorsal visual brain structures? A cross-sectional and longitudinal study

“…Although Bearden et al [49] reported an inverse pattern with greater impairments in visuo-spatial memory, these findings are generally consistent with the literature in 22q11.2DS [32–34]. Interestingly, visual ventral and dorsal functions have been previously investigated in other developmental disorders.…”

“…Visuo-constructive abilities depend on the integrity of multiple processes such as perception, visuo-spatial organization, motor functioning, and motivation [58, 59]. Consequently, many impaired processes also observed in 22q11.2DS could underly the observed difficulties during the copy part, such as spatial working memory deficits [60], executive impairments [61], perceptual [34, 62, 63], and psychomotor deficits [64]. Importantly, our results showed that both groups (22q11.2DS and TD) made more errors in the BVRT memory part compared to the copy part, indicating that the memory performance of individuals with 22q11.2DS is not only due to visuo-constructive impairments but also to memory contribution.…”

“…Evidences suggested that individuals with 22q11.2DS are more impaired in memory tasks related to the ventral stream compared to the tasks related the dorsal stream. Indeed, patients with 22q11.2DS have greater difficulties in memorizing faces or objects, whereas their memory of spatial localization seems partially impaired or even preserved [32–34]. However, these former studies have only included a limited number of tasks assessing the two streams and studied participants with a mean age ranging from 10 to 12.6 years.…”

“…The first aim was to replicate the dissociation between tasks typically linked to the ventral stream and to the dorsal streams. Then, in light with a previous study showing that intellectual disability might have an impact on the neuropsychological profile of individuals with 22q11.2DS [34], additional analyses were performed to investigate the links between visual memory capacities and IQ measures. Finally, we also explored whether visual memory deficits in participants with 22q11.2DS were related to cerebral morphological alterations in the ventral (inferior and ventral temporal cortex) and dorsal brain areas (superior parietal cortex).…”

Children With Chromosome 22q11.2 Deletion Syndrome Exhibit Impaired Spatial Working Memory

“…This suggests a double dissociation between verbal skills and visuospatial processing, which provides the foundation for numerical thinking arithmetic performance (Simon, 2008). Moreover, these impairments persist even in individuals without intellectual disability (Vicari et al, 2012), and there is reason to suspect these impairments are long lasting and will persist throughout life, as impairments are observed in adults on tasks assessing visuoperceptual ability, problem solving, and planning, as well as abstract and social thinking (Henry et al, 2002). Together, these studies suggest that some aspect of atypical visual spatiotemporal processing might lead to subsequent impairments in visuospatial memory.…”