Question

question 22

cw antigen is:

low incidence.
antithetical to f.
high incidence.
antithetical to v.

Explanation:

Define the Cw antigen

The \(C^w\) (RH8) antigen is a low-incidence antigen belonging to the Rh Blood Group System. It is a variant of the C antigen, resulting from a single amino acid substitution on the RhCe protein.

Analyze the incidence rate

Because it is found in less than \(2\%\) of most populations (approximately \(1\%\) to \(2\%\) in Caucasians and even rarer in other ethnic groups), it is classified as a low-incidence (low-frequency) antigen.

Evaluate the other options

• antithetical to f: The f antigen (\(ce\)) is a compound antigen. The antithetical partner to \(C^w\) is actually the high-incidence antigen \(MAR\), or it is considered a variant of \(C\). It is not antithetical to \(f\).
• high incidence: High-incidence antigens are present in more than \(99\%\) of the population. \(C^w\) is rare, so this is incorrect.
• antithetical to V: The \(V\) (\(ce^s\)) antigen is another low-incidence Rh antigen, not antithetical to \(C^w\).

Answer:

• low incidence. (Correct answer)
• antithetical to f.
• high incidence.
• antithetical to V.