Abstract: Objective To investigate the molecular mechanism and transfusion strategy of a RhDCCee phenotype patient with cold antibody and anti-e like antibody. Methods The blood type and irregular antibody specificity were identified by serological methods such as test tube method, microcolumn gel card method and absorption diffusion test. The blood type genes were systematically analyzed by PCR-SSP, fluorescent PCR, Sanger sequencing and third-generation sequencing. SWISS-MODEL was used to compare and analyze protein models carrying common and mutant alleles. Results ABO and Rh phenotypes were type B and RhDCCee. The irregular antibodies were positive and specific antibodies were cold antibodies and anti-e. The PCR SSP and fluorescence PCR results were both Ce/Ce. Sanger sequencing revealed the presence of c.375C>G and c.827C>A mutations. Third-generation sequencing showed that exon 2-3 were very low in sequencing depth and there might be structural variation. The SWISS-MODEL suggested that the above mutations may lead to abnormal expression of the e antigen. The patient was infused ccEE phenotype red blood cells. Conclusion Cold antibody combined with anti-e like antibody jointly interfere with blood typing and cross matching. RHCE gene c.375C>G, c.827C>A combined with structural variations in Exon2-3 lead to abnormal expression of e antigen.

Key words: Cold antibody, Anti-e like antibody, Allele, Third-generation sequencing