Abnormal development of early auditory processing in 22q11.2 Deletion Syndrome

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• 22q11.2 Deletion Syndrome (22q11.2 DS) is a significant genetic risk factor for schizophrenia spectrum disorders.
• Reduced mismatch negativity (fMMN) amplitude is a potential neurophysiological marker for schizophrenia-related brain pathology.

Purpose of the Study:

• To investigate the developmental trajectory of fMMN in individuals with 22q11.2 DS from childhood to adolescence.
• To identify neurophysiological markers associated with brain maturation and schizophrenia risk in 22q11.2 DS.

Main Methods:

• Longitudinal and cross-sectional study design using auditory oddball stimuli.
• Measurement of evoked potentials, specifically fMMN and N1 components.
• Comparison of 22q11.2 DS patients (n=16 longitudinal, n=51 cross-sectional) with age-matched controls (n=14 longitudinal, n=50 cross-sectional).

Main Results:

• Longitudinal analysis revealed a significant reduction in fMMN amplitude and altered topographic patterns in 22q11.2 DS carriers from childhood to adolescence.
• Cross-sectional data corroborated reduced fMMN amplitude in adolescents with 22q11.2 DS, while it was preserved in childhood.
• Adolescents with 22q11.2 DS showed increased auditory N1 component amplitude, unlike controls.

Conclusions:

• These findings indicate distinct developmental trajectories in auditory sensory processing for individuals with 22q11.2 DS.
• Emerging functional brain network changes during adolescence in 22q11.2 DS may relate to the heightened risk for schizophrenia spectrum disorders.