HLA-haplotype redundancy and rareness in Canadian Blood Services' Stem Cell Registry and Cord Blood Bank: Novel metrics for optimizing utility.

Redundancy was greater in the SCR compared to the CBB and was most common with CAU ethnicity. Recruiting non-Caucasian registrants and continued cord blood banking should reduce redundancy. A sub-inventory of redundant donors and cord blood units could support new uses for donor-supported cellular therapies that do not require HLA matching.