In this paper, we characterize the novel human leukocyte antigen (HLA)-DQB1*0634 allele we found in a sibling pair during high-resolution HLA typing in forecast of upcoming bone marrow transplantation. Both siblings, the female patient and her brother, were HLA identical, and therefore, both figured out the novel DQB1 allele characterized by a nucleotide exchange 'C' to 'T' at position 565, which is the last nucleotide of DQB1 exon 3. DQB1 exon 4 sequencing confirmed the exchange of codon 189-arginine (CGG), which is replaced by tryptophan (TGG) in the new allele DQB1*0634.