Atypical Hemolytic Uremic Syndrome and Nephrotic Syndrome Associated with Cytomegalovirus Infection.

Atypical hemolytic uremic syndrome (aHUS) is a rare disease. It results from the dysregulation of the alternative complement pathway on the cell surface which causes endothelial damage. Increasing evidence links, these abnormalities to mutations in genes of complement regulators or with autoantibodies against complement factors. These mutations have an incomplete penetrance and variable phenotype. Cytomegalovirus (CMV) is endemic throughout the world, and the incidence of severe CMV disease in immunocompetent adults appears to be greater than previously thought. aHUS and nephrotic syndromes associated with CMV infection are rare. Identification of triggers for aHUS manifestation in a genetically susceptible patient is extremely important since this permits a faster initiation of treatment and clinical improvement. We report a case of a man with a homozygotic deletion of CFHR3-1 whose initial presentation was aHUS and nephrotic syndromes associated with CMV infection.