The most common symptomatic primary immunodeficiency in adults, characterized by hypogammaglobulinemia with impaired antibody responses. Diverse genetic causes in subset; often sporadic. Increased risk of autoimmune disease and lymphoma.

• 1Genetic testing
• 2Clinical evaluation
• 3Family history assessment
• 4Specialized laboratory tests
• 5Imaging studies
• 6Biopsy (if applicable)

Good with Ig replacement. Chronic lung disease common despite therapy. Autoimmune complications affect 25%. Lymphoma risk increased 10-20 fold. Life expectancy improving, now approaching normal with early diagnosis.

• Genetic counseling
• Carrier screening
• Prenatal diagnosis
• Preimplantation genetic diagnosis
• Family planning