Introduction:
Defect in alternate complement pathway can cause atypical hemolytic uremic syndrome (aHUS) which is the triad of non-immune haemolytic anemia, thrombocytopenia and acute kidney injury (AKI). Mutation in regulators like factor H (FH), factor I (FI), membrane cofactor protein (MCP)/ CD46 or activators like FB or C3, remain the major underlying pathogenesis. Further, there have been studies to suggest dual complement abnormalities [1-4]. Moreover, children with aHUS present with varied manifestations ranging from renal to extra-renal manifestations like central nervous system (CNS), hepatic and cardiac involvement. Although certain complement defects like MCP, anti-FH antibody associated HUS, have a phenotypic relationship in clinical manifestations and natural history, it is not applicable to most. Hence, we tried to study the spectrum of complement abnormalities, presentation and short term outcome in pediatric aHUS.