IDENTIFICATION OF NEW DRB1-ASTERISK-07 (DRB1-ASTERISK-0703), DRB1-ASTERISK-08 (DRB1-ASTERISK-0817) AND 2 DRB3-ASTERISK (DRB3-ASTERISK-0302 AND DRB3-ASTERISK-01014) ALLELES

We report here the identification of four novel DRB alleles using a re verse hybridization (CANTYPE) assay. Molecular cloning and sequencing confirmed the initial unusual hybridization patterns, All four new all eles were detected during routine HLA typing for the Canadian Unrelate d Bone Marrow Donor Registry. DRB10703 is identical to DRB1*0701 exce pt for a single nucleotide substitution (AGA-->AGT), changing codon 29 from Arg to Ser, a so far undetected DRB polymorphism. DRB10817 diff ers from DRB1'0801 by a single nucleotide substitution (TAC-->TTC), c hanging codon 47 from Tyr to Phe. This polymorphism has not, until now been identified in DRB108 alleles. Compared with DRB3*0301, DRB3*030 2 contains a single nucleotide substitution (TAC-->CAC) at codon 30, c hanging the encoded Tyr to His. This polymorphism is typical for DRB3 02 alleles. DRB301014 is identical to DRB3*0101 except for a single s ilent nucleotide substitution (GGG-->GGA) at codon 84. This polymorphi sm has previously only been described for the DRB115012 allele. DRB1* 0817, DRB30302 and DRB3*01014 may have arisen from gene conversion, b ut DRB10703 most likely nas generated by a point mutation event. The DRB30302 allele was detected in two unrelated subjects, while the oth er three have each only been detected once.