Disparities in developmental trajectories of visuo-spatial constructive ability in Williams syndrome patients with typical deletion on chromosome 7q11.23

Abstract

Objective: Williams syndrome (WS) is known to have uneven cognitive abilities. The visuo-spatial cognition difficulties are distinct, but with some inter-individual phenotypic differences. Based on an examination of atypical deletions identified in WS patients with atypical cognitive deficits, the difficulty in visuo individual phenotypic differences. Based on an examination of atypical deletions identified in WS patients with atypical cognitive deficits, the difficulty in visuo-spatial cognition of WS patients has been attributed to a haploinsufficiency of some genes located on the deleted region in 7q11.23. We questioned the view that inter-individual differences in the visuo-spatial co cognitive ability arise only from variations in deletion and performed the fo following study. Methods: We investigated whether there were inter-individual differences in the developmental trajectories of the visuo-spatial constructive abilities by following up five unrelated WS patients with the same typical deletion on chromosome 7q11.23. The deletion includes the candidate genes contributing visuo-spatial difficulty in WS patients. We used tests with three-dimensional factors such as Benton’s three-dimensional block construction test, because these tests are considered to be more sensitive than those with only two-dimensional factors. Results: There were diverse inter-individual differences in the development of the visuo-spatial constructive abilities among the present participants who shared the same typical genomic deletion of WS. One of the participants, who used to show the visuo-spatial difficulty typical of WS, showed almost equivalent performances to typically developing adults in the visuo-spatial co construction tests with three dimensional factors at the last investigation. Conclusion: In the present study, we found a wide range of developmental trajectories in visuo-spatial constructive abilities even among the patients with a common deletion pattern of WS. The findings suggest the importance of longitudinal observation instead of simply a cross sectional study, and that attributing differences in the phenotypes entirely to genetic factors such as an atypical deletion may not be always correct.