3q29 deletion syndrome (3q29del) is associated with neuropsychiatric and neurodevelopmental phenotypes. We previously reported that graphomotor weakness is present in up to 78% of individuals with 3q29del. We have now explored nuances of the graphomotor phenotype and its association with other comorbidities in this population. Participants were…

The block design task (BDT) is a visuospatial measure that individuals with Williams syndrome (WS) perform poorly on. However, it is unclear what underlies their impaired performance. This study investigated whether poorer performance is a result of visuospatial difficulties, executive function (EF) difficulties, atypical looking strategies, or a…

We examined the cognitive, language, and instructional predictors of early word-reading ability in a sample of children with Williams syndrome longitudinally. At Time 1, sixty-nine 6-7-year-olds (mean age = 6.53 years) completed standardized measures of phonological awareness, visual-spatial perception, vocabulary, and overall intellectual…

Rett Syndrome (RTT) is characterized by severe impairment in fine motor (FM) and expressive language (EL) function, making accurate evaluations of development difficult with standardized assessments. In this study, the administration and scoring of the Mullen Scales of Early Learning (MSEL) were adapted to eliminate the confounding effects of FM…

Individuals with 22q11.2 deletion syndrome (22q11.2DS) are impaired at exploring visual information in space; however, not much is known about visual form discrimination in the syndrome. Thirty-five individuals with 22q11.2DS and 41 controls completed a form discrimination task with global forms made up of local elements. Affected individuals…

The next several pages are intended as a "Commentary" on the six target articles bundled together as a Special Issue of the "Journal of Cognition and Development"--literature reviews and research reports all intended to "build bridges" between the study of cognitive development in typical and atypical populations.

The purpose of this study was to explore the relationship between intelligence and visual motor integration skills in 5-year-old children with 22q11-deletion syndrome (22q11DS) (N = 65, 43 females, 22 males; mean age 5.6 years (SD 0.2), range 5.23-5.99 years). Sufficient VMI skills seem a prerequisite for IQ testing. Since problems related to…

Background: Fragile X syndrome (FXS) is an early diagnosed monogenic disorder, associated with a striking pattern of cognitive/attentional difficulties and a high risk of poor behavioural outcomes. FXS therefore represents an ideal model disorder to study prospectively the impact of early attention deficits on behaviour. Methods: Thirty-seven boys…

This study investigates cognitive abilities of pre/primary school children without and with spina bifida in Uganda. Qualitative semi structured interviews and quantitative functioning scales measurements were combined and conducted with 133 parents, 133 children with spina bifida, and 35 siblings. ANCOVA was used to test for differences in…

Huntington's disease (HD), an autosomal-dominant genetic disorder, has historically been viewed as a degenerative movement disorder but it also includes psychiatric symptoms and progressive cognitive decline. There has been a lack of consensus in the literature about whether or not cognitive signs can be detected in carriers before clinical…

Williams Syndrome (WS) is a developmental disorder typified by deficits in visuospatial cognition. To understand the nature of this deficit, we characterized how people with WS perceive visual orientation, a fundamental ability related to object identification. We compared WS participants to typically developing children (3-6 years of age) and…

The objective of this study was to analyze the process and product of handwriting among children with Neurofibromatosis Type 1 (NF1) in comparison to those of Typically Developing (TD) children. Children with NF1 are at risk for some cognitive deficits, a wide range of deficits in perceptual skills and, motor and visual-motor integration skills…

The present study examined the cognitive profile in Fragile X Syndrome (FXS) males, and investigated whether cognitive profiles are similar for FXS males at different levels of intellectual functioning. Cognitive abilities in non-verbal, verbal, memory and executive functioning domains were contrasted to both a non-verbal and verbal mental age…

Although research has focused primarily on the wide range of variability in the cognitive phenotype between individuals with velo-cardio-facial syndrome (VCFS), we know relatively little about the extent to which within-individual expressions of the cognitive phenotype remain stable throughout development. General cognitive functioning in the low…

Williams syndrome (WS) is a genetic disorder associated with severe visuocognitive impairment. Individuals with WS also report difficulties with everyday wayfinding. To study the development of body-, environment-, and object-based spatial frames of reference in WS, we tested 45 children and adults with WS on a search task in which the participant…