Weak D (Formerly Du)
Definition
A reduced-expression variant of the D antigen that does not agglutinate red cells with standard IgM anti-D reagent in the direct test but is detected by the indirect antiglobulin test (IAT). Weak D individuals are Rh-positive but may be mistyped as Rh-negative in a direct slide test.
Related terms
- CDE Nomenclature (Fisher-Race)
- The modern standard notation for Rh antigens, naming three antithetical pairs: C/c, D (no d), and E/e. Haplotypes such as CDe (R1),...
- D Antigen
- The most immunogenic Rh antigen, encoded by the RHD gene. Its presence defines Rh-positive; its absence defines Rh-negative. No naturally occurring anti-D...
- Indirect Antiglobulin Test (IAT)
- A two-stage serological test in which IgG antibody is incubated with red cells, unbound antibody is washed away, and anti-human globulin (Coombs...
- Rh-Hr Nomenclature (Wiener)
- An earlier notation system using alphanumeric agglutinogen codes (R0, R1, R2, Rz, r, r', r'', ry) for Rh haplotypes. Wiener's R1 corresponds...
- RHD Genotyping
- PCR-based molecular typing of the RHD gene to determine D antigen status from DNA, including from dried biological evidence where serological red...
Explained in
- The Rh Blood Group System in Forensic ContextA reduced-expression variant of the D antigen that does not agglutinate red cells with standard IgM anti-D reagent in the direct test but is detected by the in...