Abstract
Objective: Velo-cardio-facial syndrome or 22q11.2 deletion syndrome (22q11DS) is the most common known microdeletion syndrome. One of the genes in the deleted region is the catechol-O-methyltransferase (COMT) gene, which is thought to have significant effects on cognition through its influence on dopamine metabolism. The aim of the present study was to better characterize the cognitive phenotype in a large cohort children with 22q11DS compared with sibling controls and to investigate if the cognitive deficits in 22q11DS were modulated by COMT expression.
Method: The memory, executive function and attentional abilities of children with 22q11DS (n = 50) compared to sibling controls (n = 31), were measured. Also, within children with 22q11DS, a preliminary exploration was carried out of the relationship between cognitive ability and COMT genotype.
Results: Overall, the 22q11DS group had significantly reduced scores on tests of memory (especially in visual memory) and executive function (particularly in planning, working memory, and motor organization) compared with sibling controls. No association, however, was identified between COMT genotype and cognitive function.
Conclusions: Although 22q11DS children have specific cognitive deficits, differences in COMT do not account for these findings.
Acknowledgements
We would like to thank all children and their families who participated in this study and the 22q11DS-UK support group for all the help and assistance received over the years. We would also like to thank Dr Chris Barnes, Guy's Hospital, and other colleagues in clinical genetics for their help with recruiting subjects. This work was supported by a grant from the Healthcare Trust.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.