Neuropsychological capacity of Prader-Willi children: general and specific aspects of impairment.

Although most Prader-Willi syndrome children perform in the mentally retarded ranges on standardized IQ tests, it is not known if their cognitive impairments are global in nature or if they exhibit a particular pattern of strengths and weaknesses in their psychological capacities. To examine this question, a cohort of children suffering from Prader-Willi syndrome was administered a battery of neuropsychological tests. The results indicated that, relative to other cognitive capacities assessed, particularly severe deficits were noted on tasks that involved information processing using the auditory modality. No differences in cognitive capacity were found between children with a number 15 chromosome defect and those with a normal karyotype configuration. Based on these initial findings, it appears that the clinical diagnosis of Prader-Willi syndrome is more important than a karyotype configuration in understanding these youngsters' manifest cognitive deficits.