We investigated autism spectrum disorder (ASD) symptomatology, hyperactivity and affect in seven genetic syndromes; Angelman (AS; n = 104), Cri du Chat (CdCS; 58), Cornelia de Lange (CdLS; 101), Fragile X (FXS; 191), Prader-Willi (PWS; 189), Smith-Magenis (SMS; 42) and Lowe (LS; 56) syndromes (age range 4-51). ASD symptomatology was heightened in…

Aim: Prader-Willi syndrome (PWS) is a genetic disorder historically characterized by two phenotypic stages. The early phenotype in infants is associated with hypotonia, poor suck, and failure to thrive. In later childhood, PWS is associated with intellectual disability, hyperphagia, as well as growth and sex hormone deficiency. Little is known…

Previous studies suggest that individuals with Williams syndrome (WS), a rare genetically based neurodevelopmental disorder, show specific weaknesses in visual attention and response inhibition within the visuospatial domain. Here we examine the extent to which impairments in attentional control extend to the visuomotor domain using a…

A frequently noted but largely anecdotal behavioral observation in Williams syndrome (WS) is an increased tendency to approach strangers, yet the basis for this behavior remains unknown. We examined the relationship between affect identification ability and affiliative behavior in participants with WS relative to a neurotypical comparison group.…

Background: Behaviour problems and a preference for adult contact are reported to be prominent in the phenotype of Smith-Magenis syndrome. In this study we examined the relationship between social interactions and self-injurious and aggressive/disruptive behaviour in Smith-Magenis syndrome to explore potential operant reinforcement of problem…

This review critically examines the research findings which characterize the cognitive, behavioral, and neuroanatomical features of Williams syndrome (WS). This article analyzes 178 published studies in the WS literature covering the following areas: 1) General intelligence, 2) Language skills, 3) Visuospatial and face processing skills, 4)…

Background: Roifman syndrome (OMIM 300258) is a multi-system disorder with a physical phenotype that includes B-cell immunodeficiency, intra-uterine and postnatal growth retardation, spondyloepiphyseal dysplasia, retinal dystrophy and characteristic facial dysmorphism. So far, six cases, all boys, have been reported in the literature. Roifman…

Background: Few studies have investigated functional and behavioural variables of Cornelia de Lange Syndrome (CdLS) in a large sample of individuals. The aim of this study is to provide greater insight into the clinical, behavioural and cognitive characteristics that are associated with CdLS. Methods: In total, 56 individuals with CdLS…

The methodology of many studies that have identified specific genetic loci for disorders associated with mental retardation is criticized as failing to demonstrate an association between the behavior phenotype and the genetic marker. A more appropriate methodology using a multitrait-multimethod approach is suggested. (Author/JDD)

Three models of behavioral effects of genetic disorders characterized by mental retardation were compared: (1) no-specific effect model (all genetic disorders have identical behavioral outcomes); (2) totally specific model (each genetic disorder has unique outcomes); and (3) partially specific model (two or more genetic disorders share outcomes…

The study found that mentally retarded males (N=18) above 12 years of age with a fragile site on the X chromosome exhibited a highly idiosyncratic stereotypic form of gaze avoidance during greeting ceremonies. Results suggest this aberrant greeting behavior may be uniquely associated with this syndrome of mental retardation. (Author/DB)

This study compared maladaptive behavior in 23 people with Prader-Willi syndrome due to paternal deletion and in 23 age- and gender-matched subjects with maternal uniparental disomy. Controlling for IQs, the deletion cases showed significantly higher maladaptive ratings, more symptom-related distress, and more behavior problems. Findings suggest a…

A survey of the families of 62 persons with Prader-Willi syndrome examined the prevalence, topographies, and specific body locations of self-injurious behaviors. Self-injury was reported for 81% of the participants. Skin-picking was the most prevalent form with the front of the legs and head being disproportionately targeted. Incidence also varied…

Evaluation of the cognitive, behavioral, and adaptive functioning of 12 retarded men with fragile X syndrome indicated that fragile X men were largely indistinguishable from comparison groups. They were, however, significantly more likely to have achieved levels of adaptive functioning commensurate with their intellectual abilities. (Author/DB)