Sequence of a new class I null allele within the HLA-B44 specificity.
A new HLA class I null allele has been identified within the B44 group by combined serological and molecular typing of a blood donor. Based on full-length cDNA sequencing, this novel HLA-B*4419N allele was found to differ from B*4402 by one single base pair deletion at position 7 of exon 1 which results in a stop at codon 19. This mutation was confirmed by polymerace chain reaction-sequence-specific oligonucleotide probe (PCR-SSOP) hybridization on genomic DNA. Based on family typing, this new allele segregates with the haplotype A*01-B*4419N-Cw*0501-DRB1*1301-DRB3*0101. Since nonsense codons are generally associated with increased mRNA decay, we investigated B*4419N mRNA by semi-quantitative reverse transcriptase (RT)-PCR and by cDNA cloning efficiency. Comparison of B*4419N cDNA to B*4402 control cDNA and to B35 cDNA levels in the same donor, as well as the analysis of cloned inserts, revealed that the exon 1 mutation did not significantly influence B*4419N steady-state mRNA.
Bettens
F
F
Transplantation Immunology Unit, University Hospital, Geneva, Switzerland.
Tiercy
J M
JM
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D005091:Exons; D015235:HLA-B Antigens / Q000235:genetics*; D059948:HLA-B44 Antigen; D006801:Humans; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
D018076:DNA, Complementary; D015235:HLA-B Antigens; D059948:HLA-B44 Antigen