Identification of the DRB1*1313 allele in a sibling pair

Sequence-specific oligonucleotide probe hybridization (PCR/SSOP), which is now routinely used in HLA laboratories to type for alleles of the class II loci, can also detect the presence of previously unknown alleles. In the course of clinical typing for DRB1, we identified two samples with probe hybridization patterns appropriate for DRB1*1313, a previously submitted sequence that had been withdrawn. Direct sequencing showed that the two individuals carried an allele with an exon 2 sequence identical to that previously submitted for DRB1*1313.