Complement component 3 deficiency

Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.

Start free with Eleplan

Complement component 3 deficiency

ORPHA:280133Disease

Also called C3 deficiency

What it is

Complement component 3 deficiency is a rare, genetic, primary immunodeficiency characterized by susceptibility to infection (mainly by gram negative bacteria) due to extremely low C3 plasma levels. Patients typically present recurrent episodes of sinusitis, tonsillitis, and/or otitis, as well as upper and lower respiratory tract infections (including pneumonia) and skin infections, such as erythema multiforme. Autoimmune disease resembling systemic lupus erythematosus and mesangiocapillary or membranoproliferative glomerulonephritis may develop, resulting in renal failure.

Key facts

Prevalence
<1 / 1 000 000
Age of onset
Childhood
Inheritance
Autosomal recessive
Classified as
Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Gene

C3Disease-causing germline mutation(s) (loss of function)

ICD-10 codes

D84.1filed under a broader ICD-10 category — shared with 15 other rare diseases

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Cross-references

MONDO 0013417OMIM 613779UMLS C1332655

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

Powered by Eleplan

A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.

Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.