IDENTIFICATION OF 4 NEW DR52-ASSOCIATED DRB1 ALLELES - DRB1-ASTERISK-1424, ASTERISK-1425, ASTERISK-1323 AND ASTERISK-1324

Four previously unreported DR52-associated DRB1 alleles have been char acterized through DNA sequencing, contributing to the diversity of the HLA system. DRB11424 is nearly identical to DRB1*1402 in the second exon, except that it contains the ''I---A'' motif found at codons 67-7 1 common to the DRB115 alleles. DRB1*1425 contains the ''A--H'' motif , found in DRB11401 at codons 57-60, in a sequence otherwise identica l with the second exon of DRB11307. Compared with DRB1*11012, DRB1*13 23 contains three predicted amino acid changes at codons 58 (ala-->glu ), 67 (phe-->ile), and 71 (arg-->glu). The sequence of DRB11324 is id entical to exon 2 of DRB11103, except that DRB1*1324 does not contain the GAG at codon 58 characteristic of the DRB111 alleles. These new alleles may have arisen through gene conversion. and they contribute t o the complexity of the DR6 family.