Lec 3

• What is the second most important blood group system after the ABO blood group system?

  Rh blood group system
• When was the D antigen discovered?

  1939
• How many related antigens have been assigned to the Rh blood group system by the ISBT?

  50 related antigens
• Which five principal antigens are important in most clinical transfusion issues of the Rh blood group system?


  D, C, E, c, and e
• What are the three Rh genetic theories that have influenced the nomenclature of the Rh blood group system?

  • Fisher-Race terminology
  • Wiener terminology
  • Rosenfield numeric terminology
• What has modern molecular techniques established about the Rh blood group system antigens?

  They are determined by two genetic loci
• What does the Fisher-Race terminology use to denote Rh antigens?

  CDE terminology
• How is the Wiener terminology represented?


  R0, R1, R2, Rz, r, r′, r˝
• What does the Rosenfield numeric terminology represent?

  D+, C+, E-, c+, e+ = Rh:1,2,-3,4,5
• What type of antibodies are formed in the ABO system according to Landsteiner's law?

  Spontaneously formed natural occurring antibodies (IgM)
• Are anti-Rh antibodies normally present in Rh+ or Rh- persons?

  No, they are immune antibodies (IgG)
• What are the three mechanisms for weak D expression?

  • Genetic
  • Position effect
  • Partial D (Mosaic)
• What is the term for RBC with normal amounts of D antigen?

  Weak D (D u)
• What is the position effect in relation to weak D expression?

  C in trans position to D or C in cis position to D
• What is the D Mosaic/Partial D phenotype characterized by?

  Missing portion of D antigen on RBC
• What are the unusual phenotypes associated with Rh blood group system?

  • D-Deletion Phenotype
  • Rh null Phenotype
  • Rh mod Phenotype
• What is the significance of recognizing unusual phenotypes in the Rh blood group system?


  They may have implications for transfusion compatibility