Using the example shown to the right, four fields can be seen and are separated by colons. The naming of an HLA antigen begins with the HLA loci/gene: HLA-A, HLA-B, HLA-C, HLA-DP, HLA DQ, or HLA-DR, etc. An asterisk is used to separate the gene locus from the first field.
- The first field is the serological antigen/allele group of HLA glycoprotein.
- The second field denotes individual allele variants that are within the first field allele group.
- The third field involves nucleotide substitutions which may or may not be silent mutations.
- The fourth field is reserved for non-coding exon and untranslated regions (UTR) of the DNA molecule.
Letters may accompany DNA typing and are related to their expression levels.
Why is this level of detail for nomenclature necessary?
With higher resolution of HLA typing, laboratories can better predict matching and resolve ambiguities. This translates into better patient outcomes for solid organ and bone marrow transplantations. For more information, visit the
Nomenclature of HLA Alleles site.
