Molecular genetics research of a Chinese family carrying triple HLA-A alleles

Abstract

Objective To determine molecular basis of a rare HLA-A typing results carrying triple A alleles in potential allo-HSCT donor and her family. Methods HLA-A, -B, -C, -DRB1, -DQB1, -E, -F, -G of 5 members in the family were genotyped at a high-resolution level using next-generation sequencing (NGS). HLA-A of probosita was re-checked using polymerase chain reaction-sequence-based typing (PCR-SBT), and SNP oligonucleotide probes (SNP-array)were scanned with genomic DNA of probosita. Results There was 162.9Kb duplication in 6p22.1(29, 803, 377-29, 966, 301)of probosita who carried triple A alleles A*02∶01∶01, A*11∶01∶01, A*24∶02∶01. Other two family members were found to carry this haplotype: A*02∶01∶01, A*24∶02∶01, B*54∶01∶01, C*01∶02∶01, DRB1*04∶05∶01, DQB1*04∶01∶01, E*01∶01∶01∶03, F*01∶01∶01, G*01∶01∶01∶01, which as a Mendelian gene was segregated and stably transmitted through two generations. Conclusion Tiny gene duplication induces one haplotype carries two HLA-A alleles in a potential healthy donor for allo-transplantaion and stably transmits through two generations.Routine HLA typing laboratories should pay more attention to this situation and accurately report.

Keywords

• triple hla-a alleles
• haplotype
• pedigree investigation
• gene sequencing
• allo-hsct
• acute myeloid leukemia