Long-Read Next-Generation Sequencing Technologies Can Address Some Limitations of Short-Read Technologies in HLA...

Accurate HLA allele identification is essential to ensure graft-recipient compatibility. Advances in next-generation sequencing (NGS), such as those provided by Illumina and Oxford Nanopore Technologies, have improved resolution of HLA-typing.

Here, a novel HLA-C*12 allele with a silent mutation (G to A) was identified in a bone marrow donor homozygous for HLA-C*12. The allele was initially linked to HLA-C*12:03:01 by short-read NGS, but further investigation by long-read sequencing revealed the mutation to be associated with HLA-C*12:02:02. Phasing limitations of short-read NGS made accurate allele assignment difficult, but precise differentiation became possible with longer reads. The origin of the mutation was subsequently confirmed by sequencing parental samples.

This case highlights the ability of long-read sequencing to resolve cis-trans ambiguities and improve allele phasing, and to enhance accuracy for new HLA allele identification.