#35
A NOVEL DQB1*03 ALLELE REVEALED BY rSSOP AND IDENTIFIED BY SBT.
Dong-Feng Chen Ph.D. 1, Angelica DeOliveira MS 1, Sharon Peplinski BS 1, Walter Herczyk BS 1 and Nancy L. Reinsmoen Ph.D. 1. 1 Pathology, Duke University Medical Center, Durham, NC, USA .
HLA genes are highly polymorphic and the number of alleles increases continuously. Recently, in two individuals of a potential stem cell recipient
s family, we observed unusual DQB1 rSSOP typing patterns indicating existence of a potential novel DQB1*03 allele. This potential novel allele was demonstrated in the samples from the father and sister of the patient by Luminex-rSSOP (OneLambda), while a homozygous DQB1*0301 was assigned to the patient by Dynal SSP. However, the family haplotype analysis indicated that the patient might also carry this potential novel allele. DQB-SSP from OneLambda and Dynal were also performed on the sample from the father. An unusual SSP pattern was revealed by OneLambdas SSP but not by Dynals SSP. To identify this potential novel DQB1*03 allele (local name DQB1*03COR), we performed SBT on the samples from the patient and his father and sister using single-allele sequencing reagent from Protrans. The sequence data obtained from these individuals verified the existence of a novel DQB1*03 allele which is identical to the DQB1*030101 with an exception of one base substitution at codon 55 changing from CCG to CAG resulting in an amino acid change from Proline to Glutamine. This polymorphic motif distinguishes the novel DQB1*03COR from all other known DQB1 alleles. The sequence of DQB1*03COR has been submitted to the GenBank (accession: DQ026226) and WHO for official nomenclature. Based on the family analysis the haplotype carrying the DQB1*03COR has been established as following: A*2301, Cw*1505, B*0702, DRB1*1303, DRB3*0202, DQB1*03COR. The DQB1*03COR explained the unexpected DQB1 rSSOP and SSP patterns observed and may have important clinical consequence due to the amino acid substitution identified.