ASCP Specialist in Blood Banking (SBB) Practice Exam

The most common CH/RG phenotype is denoted as CH/RG:1,2,3, 11, 12. This particular phenotype indicates the presence of specific antigens on the surface of red blood cells, which are important for transfusion compatibility and can also influence the likelihood of certain blood-related illnesses.

This phenotype represents a typical configuration that is frequently observed in various populations. Understanding the commonality of this phenotype is crucial for blood banking, as it assists in matching donors and recipients, especially in regards to potential alloimmunization and transfusion reactions.

The inclusion of all five antigens—1, 2, 3, 11, and 12—demonstrates that it reflects the full profile that is often found in those who are typed for these specific CH/RG antigens. In clinical practice, this knowledge is part of ensuring safe and effective blood transfusion protocols, as recognizing prevalent phenotypes can aid in predicting and managing patient needs.

Other phenotypes mentioned in the options vary due to the presence or absence of certain antigens, which impacts the frequency of their occurrence in different populations. Therefore, identifying the most common phenotype is integral to blood banking practices.