Nomenclature for Factors of the HLA system, 1990

The WHO Committee for Factors of the HLA system met in Los Angeles on 4 November 1990.The main subjects considered were: 1.The naming of sequences differing only by silent substitutions from already identified sequences.2. The naming of a new Class I gene.3. The naming and confirming of names of Class I and Class I1 allele sequences identified since the last meeting in August 1989.4. Discussion on the naming of epitopes and gene products.This report contains complete lists of all the HLA Class I and Class I1 genes and sequences of alleles officially recognised.However, only references not previously cited are included.For a complete list of references this report should be read in conjunction with the 1989 report (1).For a complete list of all serologically defined specificities, which will not be updated until 1992, see the 1987 Nomenclature report (2, 3). So~soncot cortrlnlrm tiloat tabditrtioatSeveral sequences have been identified differing only by silent nucleotide substitutions from a previously named sequence, thus not involving a change in the amino acid sequence.It was agreed that in these cases a fifth digit should be added to the previous name.For example, as shown below, an HLA-C sequence was identified which differed