Background: An increasing number of clinicians point to similar clinical features between some children with High Intellectual Potential (HIP or "Giftedness" = Total IQ > 2 SD), and children with Autism Spectrum Disorder (ASD) without intellectual or language delay, formerly diagnosed with Asperger Syndrome. Some of these common features are social interaction impairments, special interests, and in some cases high-verbal abilities. The aim of this article is to determine whether these similarities exist at more fundamental levels, other than clinical, and to explore the literature in order to provide empirical support for an overlap between ASD and HIP. Method: First, comparative studies between ASD and HIP children were sought. Because of a lack of data, the respective characteristics of ASD and HIP subjects were explored by a cross-sectional review of different areas of research. Emphasis was placed on psychometric and cognitive evaluations, experimental and developmental assessments, and neurobiological research, following a "bottom-up" procedure. Results: This review highlights the existence of similarities in the neurocognitive, developmental and neurobiological domains between these profiles, which require further study. In addition, the conclusions of several studies show that there are differences between HIP children with a homogeneous Intellectual Quotient profile and children with a heterogeneous Intellectual Quotient profile. Conclusion: HIP seems to cover different developmental profiles, one of which might share features with ASD. A new line of investigation providing a possible starting-point for future research is proposed. Its implications, interesting from both clinical and research perspectives, are discussed.

scores of AS and HFA children on the WISC-III drawn from five different studies comparing these two populations (Ghaziuddin and Mountain-Kimchi, 2004 ; Koyama et al., 2007 ; Noterdaeme et al., 2010 ; Girardot et al., 2012 ; Planche and Lemonnier, 2012 ), and on the other the scores of HIP children derived from one study (Bessou et al., 2005 ). The results show that Full Scale IQ is higher in AS children than in HFA children in 4 of the 5 studies. The Verbal IQ score is also higher than the Performance IQ score in AS children in all these studies, and Performance IQ is higher than Verbal IQ in HFA children in 4 of the 5 studies. In addition, according to these results, Verbal IQ is always higher in children with AS than in those with HFA. In contrast, Performance IQ is higher in children with HFA than in those with AS in only 2 of the 5 studies. According to these studies, in children with AS, the subtest that is the most often well-performed is “Information” from the verbal scale, and the most often failed is “Coding.” In the children with HFA, “Block Design” from the performance scale constitutes the best performed subtest in the most of these studies, whereas “Coding” appears to be the most often failed. As expected, the scores obtained by children with HIP in the study by Bessou et al. are globally higher than those of children with AS or HFA. In this HIP group, Verbal IQ is higher than Performance IQ in 81.7% of cases, and “Similarities” obtained the highest score whereas “Coding” obtained the lowest. It can be observed that Verbal IQ reflects strength of the cognitive profile among children with AS and those with HIP, but not among children with HFA. “Coding” appears to be the least well-performed subtest in the HFA, AS and HIP groups. Marked heterogeneity can be noted across the subtests in the three groups: (1) In the HFA group, the inter-subtest difference (highest score–lowest score) ranges from 4.1 points to 6.82 points according to the studies (mean 5.46

Asperger's disorder is a pervasive developmental disorder that shares similar features of social impairment disorder, restricted interests, and repetitive behaviors with autistic disorder. Although both Asperger's disorder and autistic disorder persist into adulthood, autistic disorder is usually apparent before the age of 3, while Asperger's disorder usually manifests itself at preschool age. Asperger's disorder in the majority of cases is not associated with delay in language development and there is an increased likelihood to seek social interactions and to engage in activities and friendship with others. In contrast to autistic disorder, most Asperger's disorder patients have normal intellectual functioning and some have motor clumsiness. Although the etiology of Asperger's disorder is still undetermined, this article will review the assessment and treatment interventions that could improve the prognosis of this illness. The historical background, epidemiology, diagnostic features, differential diagnosis, and course and overall management/treatment of Asperger's disorder will be discussed. Despite the absence of a cure for Asperger's disorder, the awareness of its distinctive clinical features that differentiate it from autistic disorder could improve its prognosis and differentiate response to treatment and comorbid conditions.