White matter abnormalities in adults with 22q11 deletion syndrome with and without schizophrenia

Dysfunction of cerebral white matter (WM) is a potential factor underlying the neurobiology of schizophrenia. People with 22q11 deletion syndrome have altered brain morphology and increased risk for schizophrenia, therefore decreased WM integrity may be related to schizophrenia in 22q11DS. We measured fractional anisotropy (FA) and WM volume in 27 adults with 22q11DS with schizophrenia (n=12, 22q11DS SCZ+) and without schizophrenia (n=15, 22q11DS SCZ-), 12 individuals with idiopathic schizophrenia and 31 age-matched healthy controls. We found widespread decreased WM volume in posterior and temporal brain areas and decreased FA in areas of the frontal cortex in the whole 22q11DS group compared to healthy controls. In 22q11DS SCZ+ compromised WM integrity included inferior frontal areas of parietal and occipital lobe. Idiopathic schizophrenia patients showed decreased FA in inferior frontal and insular regions compared to healthy controls. We found no WM alterations in 22q11DS SCZ+ vs. 22q11DS SCZ-. However, there was a negative correlation between FA and PANSS scores (Positive and Negative Symptom Scale) in the whole 22q11DS group in the inferior frontal, cingulate, insular and temporal areas. This is the first study to investigate WM integrity in adults with 22q11DS. Our results suggest that pervasive WM dysfunction is intrinsic to 22q11DS and that psychotic development in adults with 22q11DS involves similar brain areas as seen in schizophrenia in the general population.