Toggle Main Menu Toggle Search

Open Access padlockePrints

Functional characterisation of rare genetic variants in the N-terminus of complement factor H in aHUS, C3G and AMD

Lookup NU author(s): Dr Edwin Wong, Thomas Hallam, Dr Vicky Brocklebank, Dr Patrick Walsh, Dr Kate Smith-Jackson, Victoria Shuttleworth, Tom Cox, Holly Anderson, Professor Kevin MarchbankORCiD, Professor Claire Harris, Professor David KavanaghORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Membranoproliferative glomerulonephritis (MPGN), C3 glomerulopathy (C3G) atypical haemolytic uraemic syndrome (aHUS) and age-related macular degeneration (AMD) have all been strongly linked with dysfunction of the alternative pathway (AP) of complement. A significant proportion of individuals with MPGN, C3G, aHUS and AMD carry rare genetic variants in the CFH gene that cause functional or quantitative deficiencies in the factor H (FH) protein, an important regulator of the AP. In silico analysis of the deleteriousness of rare genetic variants in CFH is not reliable and careful biochemical assessment remains the gold standard. Six N-terminal variants of uncertain significance in CFH were identified in patients with these diseases of the AP and selected for analysis. The variants were produced in Pichia Pastoris in the setting of FH CCPs 1-4, purified by nickel affinity chromatography and size exclusion and characterised by surface plasmon resonance and haemolytic assays as well as by cofactor assays in the fluid phase. A single variant, Q81P demonstrated a profound loss of binding to C3b with consequent loss of cofactor and decay accelerating activity. A further 2 variants, G69E and D130N, demonstrated only subtle defects which could conceivably over time lead to disease progression of more chronic AP diseases such as C3G and AMD. In the variants S159N; A161S; and M162V any functional defect was below the capacity of the experimental assays to reliably detect. This study further underlines the importance of careful biochemical assessment when assigning functional consequences to rare genetic variants that may alter clinical decisions for patients.

Publication metadata

Author(s): Wong EKS, Hallam T, Brocklebank V, Walsh P, Smith-Jackson K, Shuttleworth V, Cox T, Anderson H, Barlow PN, Marchbank KJ, Harris C, Kavanagh D

Publication type: Article

Publication status: Published

Journal: Frontiers in immunology

Year: 2021

Volume: 11

Print publication date: 01/01/2021

Online publication date: 14/01/2021

Acceptance date: 25/11/2020

Date deposited: 17/01/2021

ISSN (electronic): 1664-3224

Publisher: Frontiers Research Foundation


DOI: 10.3389/fimmu.2020.602284


Altmetrics provided by Altmetric


Funder referenceFunder name
DK was funded by Fight for Sight, the Wellcome Trust, the Medical Research Council, Kidney Research UK and Complement UK.
EKSW was funded by Northern Counties Kidney Research Fund and was an MRC clinical research fellow and an NIHR Academic Clinical Lecturer.
CLH was funded by the Medical Research Council.
KJM was funded by the Northern Counties Kidney Research Fund, the Newcastle Healthcare Charites and a Kidney Research UK project grant (RP7/2015).
KSJ is a Medical Research Council (MRC) clinical research fellow (MR/R001359/1).
supported/funded by NIHR Newcastle Biomedical Research Centre at Newcastle upon Tyne Hospitals NHS Foundation Trust.
TEC is funded by MRC Discovery Medicine North.
PW is funded by the Wellcome trust.
TMH is funded by Complement UK. VB is a Medical Research Council/Kidney Research UK Clinical Research Training Fellow (MR/R000913/1.