Complement factor I (CFI) deficiency
Written and reviewed by Dr Ibrahim Imam, Consultant Neurologist. Last reviewed .
Complement factor I (CFI) deficiency. This is caused by mutations in Chromosome 4q. Fully referenced neurology checklist.
Genetics
- This is caused by mutations in Chromosome 4q
- The transmission is autosomal recessive
- CFI inactivates the complement system: it cleaves the α′-chains of C3b and C4b
Systemic manifestations
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Neurological manifestations
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Differential diagnosis
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Magnetic resonance imaging (MRI) brain: features
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Cerebrospinal fluid (CSF) analysis
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Other investigations
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Treatment
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References
- Altmann T, Torvell M, Owens S, et al. Complement factor I deficiency: a potentially treatable cause of fulminant cerebral inflammation. Neurol Neuroimmunol Neuroinflamm 2020; pii: e689.
- Bay JT, Katzenstein TL, Kofoed K, et al. Novel CFI mutation in a patient with leukocytoclastic vasculitis may redefine the clinical spectrum of Complement Factor I deficiency. Clin Immunol 2015; 160:315-318.
- Alba-Domínguez M, López-Lera A, Garrido S, et al. Complement factor I deficiency: a not so rare immune defect: characterization of new mutations and the first large gene deletion. Orphanet J Rare Dis 2012; 7:42.
- Rolfes M, Harroud A, Zorn KC. Complement factor I gene variant as a treatable cause of recurrent aseptic neutrophilic meningitis: a case report. Neurol Neuroimmunol Neuroinflamm 2023; 10:e200121.
- Massey V, Nguyen CE, François T, et al. CNS inflammation as the first sign of complement factor I deficiency: a severe myelitis treated with intense immunotherapy and eculizumab. Neurol Neuroimmunol Neuroinflamm 2024; 11:e200191.
