Table 2.
Risk of atypical hemolytic uremic syndrome recurrence according to the implicated genetic abnormality
| Gene | Protein location | Functional impact | Mutation frequency in aHUS (%) | Recurrence frequency after transplantation (%) |
| Mutation | ||||
| CFH | Plasma | Loss | 20-30 | 75-90 |
| CFI | Plasma | Loss | 2-12 | 45-80 |
| CFB | Plasma | Gain | 1-2 | 100 |
| C3 | Plasma | Gain | 5-10 | 40-70 |
| MCP | Membrane | Loss | 10-15 | 15-20 |
| THBD | Membrane | Loss | 5 | 1 case |
| Genetic polymorphism (frequency in control population) | ||||
| Homozygous CFHR1del (3%-8%) | Circulating | Undetermined | 14-23 (> 90% in patients with anti-CFH antibodies | NA |
aHUS: Atypical hemolytic uremic syndrome; C3: Complement C3; CFH: Complement factor H; CFI: Complement factor I; CFB: Complement factor B; MCP: Membrane cofactor protein; THBD: Thrombomodulin; CFHR1: Complement factor H receptor 1; NA: Not available.