Clumsiness in autism and Asperger syndrome: a further report

Clumsiness has been proposed as a diagnostic feature of Asperger syndrome (AS), a type of pervasive developmental disorder recently introduced in the ICD-10 and DSM-IV. However, the extent to which this symptom is specific to AS is not clear. To investigate this issue, we compared a sample of AS children with age- and sex-matched groups of children with autistic disorder and pervasive developmental disorder not otherwise specified (PDDNOS). Twelve subjects with AS (ICD-10/DSM-IV; 11 males; average age 11.4 years; mean full-scale IQ 104.9) were compared with 12 subjects with autistic disorder (DSM-III-R; II males; average age 10.3 years; mean full-scale IQ 78.4) and 12 subjects with PDDNOS (DSM-III-R; 10 males; average age 10.1 years; mean full-scale IQ 78.2). The BruininksOseretsky test, a standardized test of motor coordination, was administered blind by the same investigator to all the three groups. While coordination deficits were found in all three groups, children with AS were found to be less impaired than those with autistic disorder and PDDNOS. However, no significant relationship was found between coordination scores and diagnosis after adjusting for the level of intelligence. These findings suggest that some patients with AS may be less clumsy than those with autistic disorder and that this difference may be the result of their higher level of intelligence. Studies based on larger samples using multiple measures of coordination are needed to further clarify the role of clumsiness in the classification of pervasive developmental disorders.