A novel RHCE*ce 48C, 733G allele with Nucleotide 941C in Exon 7 encodes an altered red blood cell e antigen

Several RHCE*ce alleles have in common a 733C>G (Leu245Val) change. Some encode an altered expression of e on red blood cells (RBCs) and individuals with such RBCs can make e-like alloantibodies. The identification of an apparent anti-hr(B) in the serum of an E-e+ African American patient prompted us to analyze her DNA, which revealed a novel RHCE*ce allele. We also screened blood samples from African Americans to determine the frequency of the novel allele.

Hemagglutination tests and molecular analyses were performed by standard procedures.

Analysis of the proband's DNA revealed RHCE*ce 48C/C, 733G/G, 941T/C, and 1006G/T. Of 272 samples from African Americans, 257 were RHCE*941T/T (wild type), and 15 (6%) were RHCE*941T/C. Of these 15, 14 were RHCE*ce/ce, 10 with 733C/G and four with 733G/G, and one was RHCE*ce/cE, 733C/G. Cloning experiments confirmed the Nucleotide 941 change and showed that 48C, 733G, 941C, and 1006T were carried on the same allele. RBCs from the 15 samples carrying the RHCE*941C variant typed V/VS+ and hrB+W.

This study identifies a novel allele, RHCE*ce 48C, 733G, 941C, 1006T which is predicted to encode 16Cys, 245Val, 314Ala, and 336CyS and was shown to encode c, V/VS, and an altered expression of e and hrB antigens. The clinical significance of the antibody found in the proband is not established because E+e- RBC components were transfused to the patient. The novel RHCE*ce 48C, 733G, 941C, 1006T allele was present in 5.5% of samples from African Americans and thus, in this small cohort, it had a frequency of 0.028.