Genetic analysis of CFHR1 and CFHR3 genes. Electropherograms showing the mutations identified in patients with aHUS (A) H119 (CFHR1 gene) and (B) H123 (CFHR3 gene). The 2 mutations were found in heterozygosis. The mutation in patient H123 could also be interpreted as c.838_839delAT (p.I280KfsX6). SwissProt accession numbers for protein sequences are Q03591 (CFHR1) and Q02985 (CFHR3). Nucleotide numbering is based on the translation start site; A in ATG is +1.