Atypical hemolytic-uremic syndrome: recurrent phenotypic expression of a patient with MCP gene mutation combined with risk haplotypes.

: We bring the case of a 38-year-old man who was presented to the emergency department with nausea, fever, and choluria, 4 days after the ingestion of raw oysters. Analytical study revealed thrombocytopenia and acute kidney injury that were associated to a possible thrombotic microangiopathy. Therapeutic plasma exchange was started and resolution of the manifestations was obtained. To identify the cause of the thrombotic microangiopathy a molecular study was performed and a pathogenic variant in the MCP gene, c.287-2A>G (splice acceptor) in heterozygous state with a concomitant presence of both risk haplotypes, MCPggaac and Complement factor H (CFH)-H3 were identified. These findings make the diagnosis of atypical hemolytic-uremic syndrome (aHUS), and despite a relatively benign course with a positive response to plasma exchange without an evolution to renal failure was evident a recurrent profile of aHUS when associated with an infectious trigger.