Which of the following statements is true concerning the MN genotype?

Which of the following statements is true concerning the MN genotype?

• A. Antigens are destroyed using bleach-treated cells
• B. Dosage effect may be seen for both M and N antigens
• C. Both M and N antigens are impossible to detect
• D. MN is a rare phenotype seldom found in routine antigen typing

Answer: (B)

The statement that dosage effect may be seen for both M and N antigens is accurate. In immunology, the dosage effect refers to the phenomenon where the expression of antigens can vary depending on the gene dosage present in an individual. For the M and N blood group system, which is based on the glycophorin A molecule on red blood cells, individuals who are homozygous for M or N will express a stronger reaction to the corresponding antibodies compared to heterozygous individuals. This means that individuals with the MM genotype will display a stronger M antigen expression, and those with the NN genotype will show a stronger N antigen expression when tested with serological assays. The heterozygous MN individuals will express antigens from both alleles but may not exhibit the same intensity of reactivity as the homozygous types. Understanding this dosage effect is essential for accurate antigen typing in blood banking and transfusion medicine. In contrast, the other statements do not hold true: bleach-treated cells are not specifically used to demonstrate MN antigens as bleach would destroy the antigenic structure; it is not the case that both M and N antigens are impossible to detect as they are well established; and while MN phenotypes may have varying frequencies,

The statement that dosage effect may be seen for both M and N antigens is accurate. In immunology, the dosage effect refers to the phenomenon where the expression of antigens can vary depending on the gene dosage present in an individual. For the M and N blood group system, which is based on the glycophorin A molecule on red blood cells, individuals who are homozygous for M or N will express a stronger reaction to the corresponding antibodies compared to heterozygous individuals.

This means that individuals with the MM genotype will display a stronger M antigen expression, and those with the NN genotype will show a stronger N antigen expression when tested with serological assays. The heterozygous MN individuals will express antigens from both alleles but may not exhibit the same intensity of reactivity as the homozygous types. Understanding this dosage effect is essential for accurate antigen typing in blood banking and transfusion medicine.

In contrast, the other statements do not hold true: bleach-treated cells are not specifically used to demonstrate MN antigens as bleach would destroy the antigenic structure; it is not the case that both M and N antigens are impossible to detect as they are well established; and while MN phenotypes may have varying frequencies,