Nonverbal assessment of IQ, attention, and memory abilities in children with fragile-X syndrome using the Leiter-R

This study examined the clinical utility of the recently revised Leiter Int ernational Performance Scale (Leiter-R) with a sample of children with frag ile-X syndrome. The sample included 25 male children ranging in age from 4. 0 to 12.8 years and was 92% European American. All subjects were administer ed the entire Attention and Memory Battery, and the four subtests from the Visualization and Reasoning Battery that comprise the Brief IQ composite. T hese tasks were selected to address specific concerns pertaining to memory and attention in individuals with fragile-X. Initial examination of the dat a revealed that all of the children completed the subtests comprising the B rief IQ and, outside of the Attention Divided subtest, over 80% of the chil dren completed most of the subtests on the Attention and Memory Battery Fin dings from the Leiter-R were generally consistent with previously reported assessment results with this population. Overall, the sample fell within th e mild to moderate range of mental retardation, with over 80% of the group at or below this range of functioning. As a group, relative difficulty was noted on tasks tapping selective attention and working memory. Ipsatively, a relative strength was apparent across cases on the Associated Pairs subte st. Chronological age had a significant moderate positive correlation with the Leiter-R growth score for the composite scales and a significant strong negative correlation with the age-based standard score for Brief IQ. These findings are discussed with respect to the clinical and research applicati ons of the Leiter-R for children with fragile-X as well as for children wit h other developmental disabilities.