ABO group frequencies vary according to ethnicity. This will be an important fact to consider when working through ABO discrepancy resolution. The table below delineates frequencies of ABO occurrences according to ethnic groups.
| O
| A
| B
| AB |
Asian | 40% | 28% | 25% | 7% |
Black | 51% | 26% | 19% | 4% |
Caucasian | 45% | 40% | 11% | 4% |
Hispanic | 57% | 31% | 10% | 2% |