Investigation of white matter structure in velocardiofacial syndrome: a diffusion tensor imaging study.
OBJECTIVE
Velocardiofacial syndrome, caused by a deletion on chromosome 22q11.2, is often accompanied by cognitive, behavioral, and psychiatric impairments. Specifically, velocardiofacial syndrome has been proposed as a disease model for a genetically mediated subtype of schizophrenia. Velocardiofacial syndrome is also known to affect brain structure. The most prominent structural findings in velocardiofacial syndrome are reduced white matter volumes. However, the structure of white matter and extent of specific regional involvement in this syndrome have never been investigated. The current study used diffusion tensor imaging to investigate white matter structure in children and young adults with velocardiofacial syndrome.


METHODS
Nineteen participants with velocardiofacial syndrome and 19 age- and gender-matched comparison subjects underwent diffusion-weighted magnetic resonance imaging scans. Whole brain voxel-by-voxel analyses were conducted to investigate white matter fractional anisotropy differences between the groups.


RESULTS
Relative to the comparison group, the velocardiofacial syndrome group had reduced white matter anisotropy in the frontal, parietal, and temporal regions as well as in tracts connecting the frontal and temporal lobes.


CONCLUSIONS
This study demonstrates that alterations of white matter tract structure occur in velocardiofacial syndrome. Reduced white matter anisotropy was observed in individuals with velocardiofacial syndrome in areas previously implicated in the neurocognitive phenotype of velocardiofacial syndrome. The finding of aberrant parietal white matter tracts as well as aberrant frontotemporal connectivity in velocardiofacial syndrome and in previous schizophrenia studies may be associated with increased vulnerability for development of psychotic symptoms.
D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology*; D002648:Child; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22; D019465:Craniofacial Abnormalities / Q000235:genetics / Q000473:pathology*; D004062:DiGeorge Syndrome / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006330:Heart Defects, Congenital / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D010296:Parietal Lobe / Q000473:pathology; D012559:Schizophrenia / Q000235:genetics; D013577:Syndrome; D013702:Temporal Lobe / Q000473:pathology; D014681:Velopharyngeal Insufficiency / Q000235:genetics / Q000473:pathology*