Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neuroimaging

Background:

• 22q11.2 deletion syndrome (22q11DS) is linked to abnormal brain development and connectivity.
• Resting-state fMRI studies show impaired default mode network (DMN) connectivity in 22q11DS.
• Previous research suggests a link between DMN dysfunction and psychosis.

Purpose of the Study:

• To investigate functional and structural DMN connectivity in 22q11DS.
• To examine age-related changes in DMN connectivity in 22q11DS.
• To explore the relationship between DMN connectivity and prodromal psychotic symptoms.

Main Methods:

• Acquired T1-weighted, diffusion, and resting-state fMRI scans from 41 patients with 22q11DS and 43 controls (ages 6-28).
• Used independent component analysis (ICA) to identify the DMN and define regions of interest.
• Assessed prodromal symptoms using the Structured Interview of Prodromal Syndromes (SIPS) and correlated connectivity with age and SIPS scores.

Main Results:

• Observed reduced functional and structural connectivity in core medial DMN nodes in 22q11DS.
• Structural connectivity increased with age in controls but not in 22q11DS, indicating altered developmental trajectories.
• No significant correlation found between DMN disconnectivity and prodromal symptom severity.

Conclusions:

• 22q11DS is characterized by both functional and structural DMN disconnectivity.
• Patients with 22q11DS do not develop typical structural connections within the medial DMN.
• Findings suggest aberrant neurodevelopmental pathways in 22q11DS.