Explain what HLA groups are, and their significance.
HLA stands for Human Leukocyte Antigen and is found on white blood cells, more specifically on chromosome 6. The HLA- group of an individual is determined by a combination of the three genes of the HLA- system, called A, B and C.
Each loci on the antigen have a large number of alleles, which means that it is a huge number of combinations. There are more precisely 9,5 million different ways of which they can recombinate. HLA- A has 20 combinations, B has 40 and C has 20. It is extremely rare to find two people with the same combinations. One can say that the significance of the HLA- groups is to predict if a transplant will work or not. This is not easy because of the variety. The importance is to find the ‘best match’.