Level of genotypic disparities identified within each HLA-A (A) and HLA-B (B) serotype. Each column represents the number of times a particular serotypes was matched between patients and their URD. The dark segment represents the genotypic or DNA mismatch within each serotype and the light segment represents genotypic matches. All the columns have been scaled to 100% and the data table along the x-axis shows the actual occurrences. The columns have been positioned from the left to the right in a decreasing order of prevalence of the serotypes in the URD group. Marked variation in the level of genotypic disparities between patient and sero-matched URD for different serotypes is apparent.