IDENTIFICATION OF NOVEL DRB1-ASTERISK-13 (DRB1-ASTERISK-1333), DRB1-ASTERISK-04 (DRB1-ASTERISK-0426) AND DRB5-ASTERISK (DRB5-ASTERISK-0109)ALLELES

Three novel HLA class II alleles (DRB11333, DRB1*0426, DRB5*0109) are described here. The 3 novel alleles were initially detected as previo usly unidentified SSO hybridization patterns using the CANTYPE reverse hybridization assay. Sequences were determined by cloning/sequencing. DRB11333 is identical to DRB1*1303 except for a single nucleotide su bstitution (ACC --> AAC), changing codon 77 from Thr to Asn. This poly morphism is typical for DRB103 alleles. DRB1*0426 is identical to DRB 10401 except for a single nucleotide substitution (GCC --> ACC) at co don 58, changing the encoded Ala to Thr. DRB50109 is identical to DRB 50101, except for a single nucleotide substitution (GAC --> AAC), cha nging codon 70 from Asp to Asn. Both latter polymorphisms were so far undetected in DRB alleles. DRB11333 could have arisen from a gene con version event, but DRB10426 and DRB5*0109 most likely were generated by point mutation events. For all 3 alleles, the sequence was confirme d by the original hybridization pattern (DRB11333) or by hybridizatio n to a newly designed probe (DRB10426 and DRB5*0109). Ethnic backgrou nds were Lebanese for DRB11333 and Caucasian for DRB1*0426 and DRB5*0 109.