Clinical variability and characteristic autoantibody profile in primary C1q complement deficiency.

Area of Science:

• Immunology
• Genetics

Background:

• C1q deficiency is a rare inherited disorder affecting the complement cascade's early stages.
• It is associated with increased susceptibility to infections and autoimmune diseases.

Observation:

• A large, consanguineous Pakistani family exhibited C1q deficiency across multiple generations.
• Affected individuals, including a father and five sons, displayed varied clinical manifestations.

Findings:

• Clinical presentations ranged from asymptomatic to severe bacterial infections and lupus-like syndromes affecting skin, kidneys, or CNS.
• Characteristic autoantibodies included anti-Sm and anti-Ro, but not anti-dsDNA.

Implications:

• Recognizing the broad spectrum of C1q deficiency clinical and autoantibody profiles is vital.
• Accurate diagnosis and timely management are essential for this life-threatening immunodeficiency.