Disparities in visuo-spatial constructive abilities in Williams syndrome patients with typical deletion on chromosome 7q11.23.
BACKGROUND
Williams syndrome (WS) is known for its uneven cognitive abilities, especially the difficulty in visuo-spatial cognition, though there are some inter-individual phenotypic differences. It has been proposed that the difficulty in visuo-spatial cognition of WS patients can be attributed to a haploinsufficiency of some genes located on the deleted region in 7q11.23, based on an examination of atypical deletions identified in WS patients with atypical cognitive deficits. According to this hypothesis, the inter-individual differences in visuo-spatial cognitive ability arise from variations in deletion.


METHODS
We investigated whether there were inter-individual differences in the visuo-spatial constructive abilities of five unrelated WS patients with the typical deletion on chromosome 7q11.23 that 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, which are considered to be more sensitive than those with only two-dimensional factors.


RESULTS
There were diverse inter-individual differences in the visuo-spatial constructive abilities among the present participants who shared the same typical genomic deletion of WS. One of the participants showed almost equivalent performances to typically developing adults in those tests.


CONCLUSIONS
In the present study, we found a wide range of cognitive abilities in visuo-spatial construction even among the patients with a common deletion pattern of WS. The findings suggest that attributing differences in the phenotypes entirely to genetic factors such as an atypical deletion may not be always correct.
Department of Functioning Science, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan; Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Yukako
Y
Muramatsu
Department of Perinatology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan.
Yoshihito
Y
Tokita
Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Aichi, Japan.
Seiji
S
Mizuno
Department of Functioning Science, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan. Electronic address: mihon@inst-hsc.jp.
Miho
M
Nakamura
D000293:Adolescent; D002648:Child; D002897:Chromosomes, Human, Pair 7; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D017384:Sequence Deletion; D013028:Space Perception; D014796:Visual Perception; D018980:Williams Syndrome / Q000235:genetics* / Q000503:physiopathology*; D055815:Young Adult
Inter-individual differences; Visuo-spatial construction; Williams syndrome