The social brain network in 22q11.2 deletion syndrome: a diffusion tensor imaging study

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a neurogenetic disorder.
• 22q11.2DS is linked to a 25-fold increased risk of schizophrenia.
• Individuals with 22q11.2DS and schizophrenia exhibit social cognitive deficits.

Purpose of the Study:

• To investigate white matter tracts in the social brain network of individuals with 22q11.2DS.
• To compare white matter integrity between 22q11.2DS patients and healthy controls.
• To explore the relationship between white matter integrity, social cognition, and psychosis symptoms in 22q11.2DS.

Main Methods:

• Two-tensor tractography was employed to analyze white matter.
• Diffusion Tensor Imaging (DTI) metrics were assessed in specific white matter tracts.
• Social cognition was measured using the Social Responsiveness Scale and Trait Emotional Intelligence Questionnaire.

Main Results:

• Participants with 22q11.2DS showed significant differences in DTI metrics within key tracts, including the inferior fronto-occipital fasciculus.
• 22q11.2DS group exhibited impaired social cognition scores.
• DTI metrics correlated with psychosis symptoms, differentiating between overt psychosis and prodromal symptoms.

Conclusions:

• White matter disruption, especially in the right inferior fronto-occipital fasciculus, is implicated in 22q11.2DS.
• Disrupted axonal coherence may be a biomarker for social cognitive deficits in 22q11.2DS.
• These findings highlight potential neurobiological markers for psychosis risk in 22q11.2DS.