Table 1.
classification of antigen variation |
D antigen Phenotype |
molecular basis |
representative example |
novel Rhesus antigen |
||
---|---|---|---|---|---|---|
protein variation | Mechanisms | RHD allele | trivial name | |||
partial D | qualitative change | amino acid substitution on the RBC surface | missense mutation | RHD(G355S) | DNB | Unknown |
protein segment exchange on the RBC surface | gene conversion (hybrid protein) | RHD-CE(3–6)-D | DVI type 3 | BARC | ||
weak D | quantitative change | amino acid substitution in the membrane or intracellularly | missense mutation | RHD(V270G) | weak D type 1 | Unknown |
DEL | major quantitative | grossly reduced translation or | missense mutation | RHD(M295I) in CDe | not applicable | unknown |
change | protein expression | mutation at splice site | RHD(K409K) | not applicable | unknown | |
D negative | D negative | lack of protein expression | gene deletion | RHD-Deletion | D negative | unknown |
nonsense mutation | RHD(Y330X) | not applicable | unknown | |||
Frame shift mutation | RHD(488del4) | not applicable | unknown | |||
modifying gene | defect of RHAG gene | Rhnull | unknown | |||
protein segment exchange on the RBC surface | gene conversion (hybrid protein) | RHD-CE(3–7)-D | Cdes | Unknown | ||
antithetical antigens of the RhCE protein | expression of antigen E or antigen e | amino acid substitution on the RBC surface | missense mutation at amino acid position 226 in RHCE | RHCE allele: Ala226 coding antigen e Pro226 coding antigen E | not applicable | E versus e |