[Genetic study of a rare Chinese pedigree with a recombination occurring between the HLA-A/C loci in both parents].

Abstract

Objective: To analyze a Chinese pedigree with a recombination occurring between the HLA-A/C loci in both parents.

Methods: A patient who was planning to undergo hematopoietic stem cell transplantation due to "aplastic anemia" in February 2022 was selected as the study subject. Peripheral blood samples were collected from the patient, his parents and brother. HLA-A/C/B/DRB1/DQB1 high-resolution typing was carried out by using sequence-based typing and sequence-specific oligonucleotides. The recombination was identified by pedigree analysis. The HLA haplotype of each individual was identified by genealogical analysis. The parentage possibility was determined by short tandem repeat analysis. HLA-A/C/B/DRB1/DRB345/DQA1/DQB1/DPA1/DPB1 were determined with next-generation high-throughput sequence-based typing. The recombination sites were analyzed by family study.

Results: The high parentage possibilities of the family was confirmed by short tandem repeat analysis. Recombination was found between the HLA-A*24:02 A*33:03/C*14:03 in the paternally transmitted haplotype, whilst HLA-A*01:01 A*03:01/C*08:02 was found in the maternally transmitted haplotype, which had resulted in two novel HLA haplotypes in the proband.

Conclusion: A rare case with simultaneous recombination of the paternal and maternal HLA-A/C loci has been discovered, which may facilitate further study of the mechanisms of the HLA recombination.