Are jigsaw puzzle skills 'spared' in persons with Prader-Willi syndrome?

Background: This three-part study examines previous clinical impressions that people with Prader-Willi syndrome have unusual jigsaw puzzle and word search skills. Results: Children with Prader-Willi syndrome showed relative strengths on standardized visual-spatial tasks (Object Assembly, Triangles, VMI) in that their scores were significantly higher than age- and IQ-matched peers with mixed mental retardation, but below those of age-matched normal children with average IQs. In striking contrast, children with Prader-Willi syndrome scored on par with normal peers on word searches, and they far outperformed them on the jigsaw puzzles, placing more than twice as many pieces as the typically-developing group. Within Prader-Willi syndrome, puzzle proficiency was not predicted by age, IQ, gender, degree of obesity, or obsessive-compulsive symptoms, but by genetic subtypes of this disorder. Conclusions: Findings are discussed in relation to splinter skills in autism, and to cases with autism and chromosome 15 anomalies that include the Prader-Willi region.