Showing papers by "Chantal Kemner published in 1998"
TL;DR: A two-stage genome search for susceptibility loci in autism was performed on 87 affected sib pairs plus 12 non-sib affected relative-pairs, from a total of 99 families identified by an international consortium, and a region on chromosome 7q was the most significant.
Abstract: Autism is characterized by impairments in reciprocal social interaction and communication, and restricted and stereotyped patterns of interests and activities. Developmental difficulties are apparent before 3 years of age and there is evidence for strong genetic influences most likely involving more than one susceptibility gene. A two-stage genome search for susceptibility loci in autism was performed on 87 affected sib pairs plus 12 non-sib affected relativepairs, from a total of 99 families identified by an international consortium. Regions on six chromosomes (4, 7, 10, 16, 19 and 22) were identified which generated a multipoint maximum lod score (MLS) > 1. A region on chromosome 7q was the most significant with an MLS of 3.55 near markers D7S530 and D7S684 in the subset of 56 UK affected sib-pair families, and an MLS of 2.53 in all 87 affected sib-pair families. An area on chromosome 16p near the telomere was the next most significant, with an MLS of 1.97 in the UK families, and 1.51 in all families. These results are an important step towards identifying genes predisposing to autism; establishing their general applicability requires further study.
537 citations
TL;DR: The ADHD group studied showed deficits in attention but not in impulsivity (or inhibition) and a subgroup of children with ADHD and oppositional defiant disorder had smaller N2 waves than controls, however.
Abstract: Objective
First, to differentiate between inattention and impulsivity based on type of errors made in the AX version of the Continuous Performance Task (CPT), and second, to investigate whether differences in performance between children with attention-deficit hyperactivity disorder (ADHD) and normal controls also occur in specific forms of brain activity, namely event-related potentials (ERPs), presumably related to inattention and impulsivity or inhibition.
134 citations
TL;DR: Autistic children made more saccades during the presentation of frequent stimuli (than normals and ADDH children), and between stimulus presentations, and unlike the normal and dyslexic groups, their saccadic frequency did not depend on stimulus type.
Abstract: The saccadic eye movements, generated during a visual oddball task, of autistic children, normal children, children with attention deficit disorder and hyperactivity (ADDH), and dyslexic children were examined to determine whether autistic children differed from these other groups in saccadic frequency. Autistic children made more saccades during the presentation of frequent stimuli (than normals and ADDH children), and between stimulus presentations. Also, unlike the normal and dyslexic groups, their saccadic frequency did not depend on stimulus type. This abnormal pattern of saccades may negatively influence the ability to attend to stimuli, and thereby learning processes. Suggestions are made with respect to possible abnormalities in subcortical mechanisms involved in saccade generation.
72 citations
TL;DR: It was concluded that a smaller amplitude of this peak is specific to children with ADHD, compared with both autistic children and those with dyslexia.
Abstract: Children with attention deficit disorder and hyperactivity (ADHD) were compared with two other clinical groups, namely, children with autism and children with dyslexia, with respect to several peaks of the ERP. By using these other clinical groups, it was studied whether amplitude differences between children and ADHD and normal control children, which were found in an earlier study, were specific to children with ADHD. ERPs were measured in response to stimuli in an auditory and a visual oddball task. Only with respect to the P3 and Pz, measured in response to deviant auditory stimuli, did the children with ADHD show smaller amplitudes than both autistic children and those with dyslexia. It was concluded that a smaller amplitude of this peak is specific to children with ADHD.
26 citations
TL;DR: Children with attention-deficit hyperactivity disorder who are categorized as responders or non-responders to methylphenidate (MPH) on the basis of their electrophysiological P3 response in a selective attention task differ in metabolic patterns of the D- and L-threo MPH enantiomers.
Abstract: Children with attention-deficit hyperactivity disorder who are categorized as responders or non-responders to methylphenidate (MPH) on the basis of their electrophysiological P3 response in a selective attention task differ in metabolic patterns of the D- and L-threo MPH enantiomers. Non-responders showed significantly higher plasma concentrations of both D- and L-threo MPH enantiomers.
22 citations
01 Jan 1998
TL;DR: This paper found evidence that autistic and attention deficit disordered (ADHD) children suffer from attention and information processing deficits on dichotic listening tasks, continuous performance tasks and so-called frontal tasks.
Abstract: Neuropsychological studies suggest evidence that autistic and attention deficit disordered (ADHD) children suffer from attention and information processing deficits (Kootz et al, 1981; Prior, 1987; Corkum and Siegel, 1995) Autistic and ADHD children show deficits in particular on dichotic listening tasks, continuous performance tasks and so-called “frontal tasks” (Pennington and Ozonoff, 1996)