Laforet M, Froelich N, Parissiadis A, Bausinger H, Pfeiffer B, Tongio M M
Laboratoire d'Histocompatibilité Etablissement de Transfusion Sanguine, Strasbourg, France.
Tissue Antigens. 1997 Oct;50(4):340-6. doi: 10.1111/j.1399-0039.1997.tb02884.x.
HLA class I typing performed in parallel by molecular biology and serology has revealed cases where an HLA class I allele was identified but the corresponding antigen on the cell surface was not detected. In the present report, we describe three members of a family in whom an HLA-A24 allele identified at the molecular level was typed as A "blank" by lymphocytotoxicity. This serologically blank antigen was nevertheless faintly detectable by isoelectric focusing (IEF) and FACS analyses. Sequencing of the HLA-A24 allele from the promoter region to the eighth exonic region revealed a point mutation in the acceptor site of the second intron as compared to the normal HLA-A24 allele. This mutation could lead to incorrect processing of mRNA through a cryptic acceptor site located at the beginning of the third exon and hence to alternative splicing with a frame shift introducing an early stop codon into the fourth exon.
