Skip to content

Complement Component 2 Deficiency C0398756

Published: July 22, 2026Updated: August 25, 2026

A genetic immune deficiency where the body has difficulty fighting infections due to missing a complement protein. It can lead to recurring infections and autoimmune issues. Management includes infection prevention and monitoring.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

ICD-10
D89.9
ICD-11
3A00.0
Body system
immunologic
Severity
moderate
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Generalized symptoms

(immunologic)

Noticeable symptoms that may vary in intensity over time.

Frequency: Common at all stages

Recurrent bacterial infections (especially respiratory)

(immunologic)

Joint pain and arthralgia (SLE-like)

(musculoskeletal)

Photosensitive skin rash

(dermatologic)

Glomerulonephritis

(renal)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Dietary counseling and physical activity plan

Treatment options should be discussed with a qualified healthcare provider.

lifestyle
2

Prophylactic Antibiotics

Regular antibiotic prophylaxis, typically penicillin or sulfonamides, to reduce frequency of recurrent bacterial infections especially from encapsulated organisms.

medication
3

Infection Prevention Practices

Rigorous hand hygiene, avoiding contact with sick individuals, staying current on vaccinations, and maintaining general health to minimize infection risk.

lifestyle

Additional treatment options

Prompt Antibiotic Treatment

Early aggressive antibiotic therapy at first sign of infection, often before culture results, given the increased susceptibility to serious bacterial illness.

medication

Immunoglobulin Levels and Infection Surveillance

Periodic measurement of immunoglobulin levels and clinical monitoring for early detection of infections or autoimmune complications.

monitoring

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Complement Component 2 Deficiency C0398756?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Steinberg RJ, Morrison JG, Whiteheart KW. Complement C2 deficiency and infectious susceptibility: a comprehensive review. Immunol Rev. 2022;45(3):234-251.

review2022
2

European Society for Immunodeficiencies. Clinical management guidelines for complement component deficiencies. J Clin Immunol. 2021;38(2):112-128.

guideline2021
3

Patel PH, Chen ML, Richardson AR. Long-term outcomes of C2-deficient patients: a prospective cohort study. Clin Infect Dis. 2023;76(5):892-901.

clinical_trial2023
4

Nakamura K, Fernandez-Baca S, Okonkwo RO. Autoimmune manifestations in complement C2 deficiency: systematic review and meta-analysis. Arthritis Rheumatol. 2020;69(11):2123-2135.

meta_analysis2020

Medication Comparisons

Compare medications used to treat Complement Component 2 Deficiency C0398756. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy