Duffy Blood Group Flashcards
Exam 2
Are the Duffy antigens well developed on fetal red cells?
Yes
What are the 3 alleles inherited at the Fy locus?
Fy(a), Fy(b), Fy
What is the most common Duffy phenotype in white populations?
Fy(a+b+)
What is the most common Duffy phenotype the black populations?
Fy(a-b-)
Are the Duffy antigens destroyed or enhanced when treated with enzymes?
Destroyed
Are the Duffy antibodies usually IgM or IgG?
IgG
At what temperature to the Duffy antibodies react best?
37C
Which Duffy antibody is most commonly seen?
Anti-Fy(a)
Do the Duffy antibodies cause transfusion reactions and HDFN?
Yes
Do the Duffy antibodies bind complement?
Rarely
Describe how the Fy(a-b-) phenotype is formed in the black population?
There is an Fy(b) variant (a change in the promoter gene) that disrupts the binding site for mRNA transcription. Therefore the Fy(b) protein is never made.
Why don’t the black population with the Fy(a-b-) phenotype usually make anti-Fy(b)?
The Fy(b) is still expressed on tissues, so the antigen is not seen as foreign. Therefore, no antibody is made.
Describe how the Fy(a-b-) phenotype is formed in the white population?
A mutation that prevents Duffy proteins form forming on RBCs as well as tissues. These individuals can make an anti-Fyb.
Describe the characteristics of Fy(x).
A weak form of Fy(b) is inherited causing reduced glycoproteins on the RBC. These individuals may type as Fy(b)-. These individuals will have depressed Fy3 and Fy5 antigens as well.
What group of individuals are capable of making an anti-Fy3 antibody?
Whites with the Fy(a-b-) phenotype that are completely lacking all duffy proteins (including Fy3)
