Table 1.

Definitions of HLA typing resolutions and allele groups. For example, HLA alleles whose names share the same first two fields code for identical amino acid sequence. Hapl-o-Mat is able to translate between these typing resolutions and groups

Resolution/group	Definition
1 field	HLA alleles of identical allele group
2 fields	HLA alleles with identical amino acid sequences
3 fieldsa	HLA alleles with identical nucleotide sequences within the coding region
4 fieldsa	HLA alleles with identical nucleotide sequences within coding and non-coding (introns or 5' or 3' untranslated) regions
G	HLA class I (II) alleles with identical nucleotide sequences across exons 2 and 3 (2)
P	HLA class I (II) expressed alleles with identical amino acid sequences across exons 2 and 3 (2)
g	HLA class I (II) expressed and null alleles with identical amino acid sequences across exons 2 and 3 (2)

^aWithin the HLA nomenclature, 2 field designations comprise more field designations if the 2 field designation actually groups more than one allele, only. If the 2 field designation is already the full length designation, it is used as equivalent to 3 and 4 field designations in this paper