Molecular, serological and genetic studies on two new HLA‐DRB1 alleles – HLA‐DRB1*0704 and HLA‐DRB1*1507

Publisher Website
Google Scholar
Abstract
Acknowledgments: We thank ROS and LJM for their help and interest in this work and Dr Helen Bass, from our laboratory, for the production of EBV‐transformed B‐cell lines. The financial support of the British Bone Marrow Donor Appeal is gratefully acknowledged. Two new HLA‐DRB1 alleles (DRB1*0704 and DRB1*1507) were detected during routine polymerase chain reaction (PCR)‐based typing of two Caucasoid bone marrow panel donors due to apparent DRB1*“blanks” being associated with unexpected DRB4, DRB5 and DQB1 alleles. HLA‐DRB1*0704 differed from DRB1*0701 by five consecutive nucleotides at positions 217 to 221 of exon 2 encoding two amino acids substitutions of tyrosine to asparagine at codons 77 and valine to tyrosine at codon 78. DRB1*1507 differed from DRB1*1501 by a single nucleotide at position 127 encoding an amino acid substitution of phenylalanine to tyrosine at codon 47. Their specificities were unequivocally assigned by serology as HLA‐DR7 and DR15, respectively, and family and population studies allowed their likely HLA‐A,B,C,DR,DQ and complement (Bf, C4A, C4B) bearing haplotypes to be identified. No further examples were found in 19,113 HLA‐DR,DQ typed donors from the Welsh Bone Marrow Donor Registry indicating that both these alleles have a phenotype frequency of <0.01% and a gene frequency of <0.00003 ( 1).