Complement Activation in 22q11.2 Deletion Syndrome

Area of Science:

• Immunology
• Genetics
• Complement System

Background:

• 22q11.2 deletion syndrome (22q11.2 del), or DiGeorge syndrome, is a common genetic disorder with diverse clinical manifestations.
• While cardiac, immune, and psychiatric issues are frequent, the role of the complement system remains unexplored.

Purpose of the Study:

• To investigate the complement system's function and activation in patients with 22q11.2 del.
• To correlate complement parameters with clinical and immunological features.

Main Methods:

• Assessed functional capacity of classical, lectin, and alternative complement pathways.
• Measured complement activation products (C3bc, TCC) in 69 patients and 56 controls.
• Correlated findings with clinical data, including psychiatric disorders.

Main Results:

• Patients with 22q11.2 del exhibited normal classical and alternative pathway function and no increased mannose-binding lectin deficiency.
• Significantly elevated C3bc and slightly increased TCC levels were observed in patients compared to controls.
• Increased complement activation correlated with the presence of psychiatric disorders.

Conclusions:

• The study demonstrates no complement deficiencies in 22q11.2 del.
• Evidence suggests heightened complement activation in these patients.
• Complement activation is specifically associated with psychiatric manifestations in 22q11.2 del.