Table 1.

Classification of HUS

Name	Causes
STEC-HUS	Infection with Shiga toxin–secreting strains of Escherichia coli or Shigella dysenteriae
Pneumococcal-HUS	Infection with neuroaminidase-producing Streptococcus pneumoniae
Atypical HUS
Complement-mediated	Mutations (mostly heterozygous) in CFH, CFI, MCP, C3, CFB, and THBD genes; genomic rearrangements of CFH/CFHR loci; anti-CFH autoantibodies
DGKE-deficiency associated	Homozygous and compound heterozygous mutations in the DGKE gene
Cobalamin deficiency–associated HUS	Homozygous mutations in the MMACHC gene
Secondary HUS	Drugs (quinine, VEGF inhibition, antiviral, cancer chemotherapy), autoimmune diseases (SLE, scleroderma, antiphospholipid syndrome), malignancy, bone marrow transplantation

Abbreviations: CFB, complement factor B; CFH, complement factor H; CFHR, complement factor H–related; CFI, complement factor I; DGKE, diacylglycerol kinase ε; HUS, hemolytic uremic syndrome; MCP, membrane cofactor protein; MMACHC, methylmalonic aciduria and homocystinuria type C; STEC-HUS, Shiga-like toxin–producing Escherichia coli HUS; SLE, systemic lupus erythematosus; THBD, thrombomodulin; VEGF, vascular endothelial growth factor.