Classical and non-classical presentations of complement factor I deficiency: two contrasting cases diagnosed via genetic and genomic methods

Research output: Contribution to journalArticlepeer-review


  • Adrian Shields
  • Alistair T Pagnamenta
  • Andrew J Pollard
  • OxClinWGS
  • Jenny C Taylor
  • Holger Allroggen
  • Smita Y Patel

Colleges, School and Institutes

External organisations

  • Department of Clinical Immunology, John Radcliffe Hospital, Oxford, United Kingdom.
  • University of Oxford
  • Department of Neurology, University Hospital Coventry, Coventry, United Kingdom.


Deficiency of complement factor I is a rare immunodeficiency that typically presents with increased susceptibility to encapsulated bacterial infections. However, non-infectious presentations including rheumatological, dermatological and neurological disease are increasingly recognized and require a high-index of suspicion to reach a timely diagnosis. Herein, we present two contrasting cases of complement factor I deficiency: one presenting in childhood with invasive pneumococcal disease, diagnosed using conventional immunoassays and genetics and the second presenting in adolescence with recurrent sterile neuroinflammation, diagnosed via a genomic approach. Our report and review of the literature highlight the wide spectrum of clinical presentations associated with CFI deficiency and the power of genomic medicine to inform rare disease diagnoses.


Original languageEnglish
Article number1150
Number of pages10
JournalFrontiers in immunology
Publication statusPublished - 7 Jun 2019


  • complement deficiency, complement factor I, genomic medicine, neuroinflammation, pneumococcal infection, primary immunodeficiency, Complement factor I, Genomic medicine, Complement deficiency, Neuroinflammation, Pneumococcal infection, Primary immunodeficiency

ASJC Scopus subject areas