Complement dysregulation associated with a genetic variant in factor H-related protein 5 in atypical hemolytic uremic syndrome.

Decreased secretion of the product of the mutant allele could explain the low FHR5 levels in patient serum. Reduced hemolysis when rFHR5 was added to serum suggests a regulatory role regarding complement activation on red blood cells. As such, low levels of FHR5, as demonstrated in the patient, may contribute to complement activation. A higher resolution version of the Graphical abstract is available as Supplementary information.