ABO group frequencies vary according to ethnicity. This will be an important fact to consider when working through ABO discrepancy resolution. Table 2 delineates frequencies of ABO occurrences according to ethnic groups.
Table 2. Blood Type Frequency by Ethnicity.1| Ethnicity | O
| A
| B
| AB |
| Asian | 40% | 28% | 25% | 7% |
| Black | 51% | 26% | 19% | 4% |
| Caucasian | 45% | 40% | 11% | 4% |
| Hispanic | 57% | 31% | 10% | 2% |
80% of A individuals are A1, while approximately 20% of A individuals are A2. The same percentages apply to AB individuals; 80% of AB individuals are A1B, while 20% of AB individuals are A2B.
1. American Red Cross. (2021). Facts About Blood and Blood Types. American Red Cross | Blood Services. http://www.redcrossblood.org/learn-about-blood/blood-types.
