Lumbreras, JavierSubias, MartaEspinosa, NataliaFerrer, Juana MariaArjona, EmiliaRodriguez de Cordoba, Santiago2024-09-132024-09-132020-07-16Lumbreras J, Subias M, Espinosa N, Maria Ferrer J, Arjona E, Rodriguez De Cordoba S. The Relevance of the MCP Risk Polymorphism to the Outcome of aHUS Associated With C3 Mutations. A Case Report. Front Immunol. 2020 Jul 16;11:1348.1664-3224http://hdl.handle.net/20.500.13003/10043https://hdl.handle.net/20.500.12105/22920Thrombotic microangiopathy (TMA) has different etiological causes, and not all of them are well understood. In atypical hemolytic uremic syndrome (aHUS), the TMA is caused by the complement dysregulation associated with pathogenic mutations in complement components and its regulators. Here, we describe a pediatric patient with aHUS in whom the relatively benign course of the disease confused the initial diagnosis. A previously healthy 8-year-old boy developed jaundice, hematuria, hemolytic anemia, thrombopenia, and mild acute kidney injury (AKI) in the context of a diarrhea without hypertension nor oliguria. Spontaneous and complete recovery was observed from the third day of admission. Persistent low C3 plasma levels after recovery raised the suspicion for aHUS, which prompted clinicians to discard the initial diagnosis of Shigatoxin-associated HUS (STEC-HUS). A thorough genetic and molecular study of the complement revealed the presence of an isolated novel pathogenic C3 mutation. The relatively benign clinical course of the disease as well as the finding of ade novopathogenic C3 mutation are remarkable aspects of this case. The data are discussed to illustrate the benefits of identifying the TMA etiological factor and the relevant contribution of the MCP aHUS risk polymorphism to the disease severity.enghttp://creativecommons.org/licenses/by/4.0/C3MCP risk polymorphismAtypical hemolytic uremic syndromeDe novomutationCase reportChildMaleMembrane Cofactor ProteinMutationHumansComplement C3Atypical Hemolytic Uremic SyndromePolymorphism, Single NucleotidePedigreeresearch articleAttribution 4.0 International3276549411134810.3389/fimmu.2020.01348Frontiers in Immunologyopen accessComplemento C3Proteína Cofactora de MembranaHumanosPolimorfismo de Nucleótido SimpleNiñoLinajeSíndrome Hemolítico Urémico AtípicoMutaciónMasculino2-s2.0-85088795730556770600001L632466400