RESUMO
The RH blood group system is the most complex with over 50 antigens. So far over hundreds of RhCE variant alleles have been described resulting in weakened and/or partial expression of RhCE antigens [1], some variant Rh phenotypes are caused by exchange of genetic material between the RHD and RHCE genes, resulting in many hybrid genes, other phenotypes result from missense mutations. Variant alleles encode altered phenotypes with either weakened antigens, lacked antigens, or unexpected antigens. Besides, the mutation of RH blood group genes may lead to the changes of Rh antigen epitopes. RHCE gene mutations or polymorphisms may bring about altered RH antigens in quality and quantity [2]. Serologic weaknesses or discrepancies are regularly faced by blood transfusion laboratories, and molecular background explaining this feature can be precisely characterized only by the molecular biological methods.
