Molecular background of RH in Bastiaan, the RH:-31,-34 index case, and two novel RHD alleles.

Anti-hr(B) (-RH31) and anti-Hr(B) (-RH34) were found nearly 40 years ago in the serum of a South African woman. The anti-hr(B) was revealed after adsorption with DcE/DcE red blod cells (RCBs). Numerous anti-hr(B), in the absence of anti-Hr(B), have since been identified. We obtained a sample of blood from this index case (Bastiaan) and report the molecular basis of her D+C-E-c+e+/-, V-VS+Hr+hr(S)+hr(B)-Hr(B)- phenotype as well as results of testing her RBCs using currently available regents. We tested a cohort of African Americans to estimate the frequency of the RHCEce 48C,733G,1006T allele, and in addition found two novel RHD alleles. Hemagglutination tests and DNA analyses were performed by standard methods. Analyses revealed homozygosity for RHCEce 48C,733G,1006T in Bastiaan. RBCs from Bastiaan were strongly agglutinated by three commercial anti-e reagents. Testing RBCs from people homozygous for RHCEce 48C,733G,1006T showed that anti-e MS16, MS17, and MS63 were weakly reactive or non reactive, MS21 was strongly reactive, and HIRO38, HIRO41, and HIRO43 were non reactive. Results show that Bastiaan has RHDDIIIa150C and RHDDIIIa-CE(4-7)-D. Tests on 605 samples from random African Americans revealed a frequency of 0.036 for RHCEce 48C,733G,1006T and revealed two novel alleles: RHD186T and RHDDIIIa150C. The Bastiaan phenotype is encoded by RHDDIIIa150C-RHCEce 48C,733G,1006T and RHDDIIIa-CE(4-7)-D-RHCEce 48C,733G,1006T ; thus, this genotype is the gold standard for the hr(B)-Hr(B)-phenotype. The r'(s) complex encodes VS, which explains why most hr(B)-RCBs are VS+.