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Start free with EleplanImmunodeficiency due to a classical component pathway complement deficiency
ORPHA:169147Disease
Also called Immunodeficiency due to C1, C4, or C2 component complement deficiency · Immunodeficiency due to an early component of complement deficiency
What it is
A rare primary immunodeficiency due to a deficiency in either complement components C1q, C1r, C1s, C2 or C4 characterized by increased susceptibility to bacterial infections, particularly with encapsulated bacteria, and increased risk for autoimmune disease. Most commonly, these include systemic lupus erythematosus (SLE), SLE-like disease, Henoch-Schonlein purpura, polymyositis and arthralgia. Disease severity is variable and dependent on the complement affected.
Key facts
- Inheritance
- Autosomal recessive
- Classified as
- Disease
Genes
ICD-10 codes
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
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.
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