AUTHOR=Shields Adrian M. , Pagnamenta Alistair T. , Pollard Andrew J. , OxClinWGS , Taylor Jenny C. , Allroggen Holger , Patel Smita Y. , Taylor Jenny C. , Knight Samantha J. L. , Pagnamenta Alistair T. , Popitsch Niko , Camps Carme , Pentony Melissa M. , Kvikstad Erika M. , Lange Lukas , Hashim Mona , Harris Steve , Tilley Mark , Vavoulis Dimitris , Kaisaki Pamela , Ragoussis Vassilis , Feral Matteo , Schuh Anna H. , Dreau Helene , Ridout Kate E. , Robbe Pauline , Antoniou Pavlos , Salminen Outi , Cabes Maite , Lopez Laura , Hamblin Angela , Taylor John , Smith Conrad TITLE=Classical and Non-classical Presentations of Complement Factor I Deficiency: Two Contrasting Cases Diagnosed via Genetic and Genomic Methods JOURNAL=Frontiers in Immunology VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01150 DOI=10.3389/fimmu.2019.01150 ISSN=1664-3224 ABSTRACT=

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.