DQB1 intron 3 sequences provide an insight into the evolution of DQB1 alleles and form the basis for intron-based sequencing.

The goal of this project was to obtain sequences of intron 3 of DQB1 in order to develop a sequencing-based typing protocol that provides a complete DQB1 exon 3 sequence. Current protocols do not provide complete sequences of exon 3, thus not allowing to differentiate common and well-documented alleles DQB1*0301 and *0319 and resolve some common trans-ambiguities with group-specific sequencing primer (GSSP) sequencing using positions 641 and 650. Samples homozygous for the most common DQB1 alleles were used to obtain intron 3 sequences, which were used to design intron-based primers for exon 3 amplification.

New HLA-DR haplotypes containing the DRB6 pseudogene.

An unexpected probe reaction pattern was observed in two samples during HLA-DR typing by PCR-Sequence Specific Oligonucleotide Probes. In order to confirm the unusual typings, samples were analyzed by PCR-Sequence Specific Primers, cloning, and nucleotide sequencing of the second exon of the HLA-DRB-genes. The confirmed DR, DQ phenotype for one sample was DRB1*0701, DRB4*01, DRB5*0101, DRB6*0201, DQB*0602, DQB1*0202.