title: Identification of the new allele B*3556 and extension of the sequences of B*4420 and B*4427.
abstract: A new B*35 allele, B*3556, was identified in a Caucasian individual. Direct sequencing of exons 2 and 3 revealed that B*3556 was identical to B*3503, except for a nucleotide substitution from G to A at position 302, which causes a change from AGC to AAC at codon 101. This results in an amino acid change from Ser to Asn at position 77 of the mature protein. Two B*44 alleles, B*4420 and B*4427, were detected in a liver recipient and in an unrelated bone marrow donor, respectively, and their sequences were confirmed. The sequences of exons 1,4 and 5 were also elucidated; for B*4420, these exons proved to be identical to those of B*440201. The sequence of exon 5 of B*4427 showed three mismatches with that of B*440201, implicating that it probably arose from B*440201 by allele conversion with an allele of the B*15, 45, 46, 49 or 50 allele group. Elucidation of the sequence of introns 3 and 4 indicated that the breakpoint for allele conversion has to be located in intron 3 or exon 4.
authors.affiliation: Tissue Typing Laboratory, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
authors.forename: C E M
authors.initials: CE
authors.lastname: Voorter
authors.forename: T
authors.initials: T
authors.lastname: Gervais
authors.forename: E M T
authors.initials: EM
authors.lastname: Mulkers
authors.forename: D
authors.initials: D
authors.lastname: Latinne
authors.forename: E M
authors.initials: EM
authors.lastname: van den Berg-Loonen
mesh_terms: D000483:Alleles; D001483:Base Sequence; D001853:Bone Marrow / Q000378:metabolism; D016026:Bone Marrow Transplantation; D005091:Exons; D015235:HLA-B Antigens / Q000235:genetics*; D059948:HLA-B44 Antigen; D006239:Haplotypes; D006801:Humans; D008099:Liver / Q000378:metabolism; D016031:Liver Transplantation; D008969:Molecular Sequence Data; D017354:Point Mutation; D017422:Sequence Analysis, DNA
chemical_list: D015235:HLA-B Antigens; C471439:HLA-B*44:27 antigen; D059948:HLA-B44 Antigen