Complement deficiency

MONDO:0003832

A genetic deficiency of any of the component of the complement system (including the classical, alternative, and terminal pathway components), that can either be acquired or inherited.

Also known as: complement activation disease, complement deficiency, disorder of complement activation, immunodeficiency due to a complement cascade component deficiency

68 clinical trials for this condition and its sub-types, 2 tagged with Complement deficiency itself.

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Where it sits in the disease tree

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Part of

↑ Immunodeficiency disease (776) ↑ Inborn error of immunity (343)

Sub-types of Complement deficiency

Atypical hemolytic-uremic syndrome 19 trials
4 sub-types
Classic complement early component deficiency 0 trials · 7 incl. sub-types
13 sub-types
- C1 inhibitor deficiency 5 trials
- Complement component 3 deficiency 2 trials
- Complement component 2 deficiency 0 trials
- Complement component 4a deficiency 0 trials
- Complement component 4b deficiency 0 trials
- Complement component 5 deficiency 0 trials
- Complement component 6 deficiency 0 trials
- Complement component 7 deficiency 0 trials
- Complement component 9 deficiency 0 trials
- Complement component C1r/C1s deficiency 0 trials
- Complement component C1s deficiency 0 trials
- Type I complement component 8 deficiency 0 trials
- Type II complement component 8 deficiency 0 trials
Disorder of lectin complement activation pathway 0 trials · 1 incl. sub-types
3 sub-types
- Mannose-binding lectin deficiency 1 trial
- Immunodeficiency due to MASP-2 deficiency 0 trials
- Immunodeficiency due to ficolin3 deficiency 0 trials
Complement factor I deficiency 0 trials
Complement receptor deficiency 0 trials
Immunodeficiency due to a classical component pathway complement deficiency 0 trials
6 sub-types
- C1Q deficiency 0 trials Sub-types →
- Complement component 2 deficiency 0 trials
- Complement component 4a deficiency 0 trials
- Complement component 4b deficiency 0 trials
- Complement component C1r/C1s deficiency 0 trials
- Complement component C1s deficiency 0 trials
Immunodeficiency due to a late component of complement deficiency 0 trials
6 sub-types
- Complement component 5 deficiency 0 trials
- Complement component 6 deficiency 0 trials
- Complement component 7 deficiency 0 trials
- Complement component 9 deficiency 0 trials
- Type I complement component 8 deficiency 0 trials
- Type II complement component 8 deficiency 0 trials
Recurrent Neisseria infections due to factor D deficiency 0 trials

Most studied deeper sub-types

Atypical hemolytic-uremic syndrome with B factor anomaly (0) Atypical hemolytic-uremic syndrome with C3 anomaly (0) Atypical hemolytic-uremic syndrome with I factor anomaly (0) Atypical hemolytic-uremic syndrome with MCP/CD46 anomaly (0) Atypical hemolytic-uremic syndrome with thrombomodulin anomaly (0) C1Q deficiency 1 (0) C1Q deficiency 2 (0) C1Q deficiency 3 (0)

Including sub-types (68) Tagged with Complement deficiency (2)

Not yet finished but already full! 1 Completed 1

Immune system proteins may worsen kidney disease in diabetes, new study investigates

Knowledge-focused By invitation only

This study looks at how the complement system, a part of the immune system, may contribute to kidney damage in people with diabetes. Researchers will measure complement proteins in blood and urine from 90 participants to see if they are linked to kidney disease severity and blood…

Sponsor: University Medical Centre Ljubljana • Aim: Knowledge-focused

Last updated Jun 27, 2026 09:08 UTC

Complement deficiency

Where it sits in the disease tree

Most studied deeper sub-types

Immune system proteins may worsen kidney disease in diabetes, new study investigates