G^u, a Variant of G

Abstract

G u , analogous to D u and E u , is a weak variant of G appearing in a haplotype lacking C, D, and E but having e s . In a preliminary survey, the red blood cells ot three of 186 Negro blood donors found negative when tested for C, D (incuding D u ), and E were shown to be G u ‐positive when tested with anti‐CD by the antiglobulin technic. Fourteen additional examples from unrelated persons and five members of a family have been investigated in this study. All G u ‐positive individuals tested are VS‐positive, but V‐negative, and all are Negro. Although G cells show greater antibody uptake when used to absorb anti‐CD, G u cells elute anti‐G in substantially greater amounts than do G cells. Comparative studies demonstrate similarity of specificity but a difference of avidity, which could be due to the influence of e s (VS) in cis position. G u ‐positive bloods have been shown to stimulate the production of anti‐G in Rh‐negative recipients. The test for G u can be incorporated in the test for D u by substituting anti‐CD or anti‐CDE for anti‐D serum.