Sequence-specific oligonucleotide probe hybridization (PCR/SSOP), whic
h is now routinely used in HLA laboratories to type for alleles of the
class II loci, can also detect the presence of previously unknown all
eles. In the course of clinical typing for DRB1, we identified two sam
ples with probe hybridization patterns appropriate for DRB11313, a pr
eviously submitted sequence that had been withdrawn. Direct sequencing
showed that the two individuals carried an allele with an exon 2 sequ
ence identical to that previously submitted for DRB11313.