{
  "abstract": "Background: ABO subtypes are characterized by attenuated antigen expression, rendering them susceptible to serological misclassification and posing substantial risks to transfusion safety. Splice-site variants represent one of the mechanisms underlying ABO subtype formation; however, previous mechanistic investigations have predominantly focused on the 5′ splice-site(5′SS), leaving the functional consequences of 3′ splice-site (3′SS) variants largely unexplored.\n\nMethods: Serological phenotyping of a proband with ABO grouping discrepancy was performed using tube agglutination, microcolumn gel agglutination, and absorption-elution assays. Genotyping was resolved by long-range PCR coupled with Nanopore sequencing. The splicing impact of this novel variant and two previously reported variants, c.29-3C>G and c.29-10T>A, was predicted in silico and validated by in vitro minigene assay. Computational saturation mutagenesis was further deployed to systematically delineate a preliminary framework of regulatory principles governing 3′SS variation.\n\nResults: A novel 3′SS variant, c.29-2A>G, was identified in an ABO*A1.02 background in a proband with an A el phenotype. This novel variant and two previously reported variants disrupted the canonical 3’SS of intron 1, converging on exon 2 skipping as the predominant aberrant splicing event. Additionally, c.29-10T>A activated a cryptic acceptor site, generating a secondary transcript with an 8-bp intronic retention. All aberrant transcripts disrupt the open reading frame and introduce premature termination codons. Through computational saturation mutagenesis, we further established an initial position- and base-dependent risk stratification model for 3′SS variants.\n\nConclusion: This study provides the first direct mechanistic evidence linking ABO 3′SS variants to subtype pathogenesis, demonstrating that exon 2 skipping constitutes a shared molecular lesion across intron 1 3′SS variants, ultimately leading to attenuated blood group antigen expression. The preliminary computationally derived risk stratification framework established herein offers a clinically valuable reference for interpreting 3′SS variants, with implications that extend beyond blood group genetics to the broader landscape of splicing-mediated human diseases.",
  "abstract_shown": true,
  "affiliations": [
    "Blood Grouping Reference Laboratory, Chengdu Blood Center , , ,"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Hongli Guan"
    },
    {
      "affs": [
        0
      ],
      "name": "Yalan Yang"
    },
    {
      "affs": [
        0
      ],
      "name": "Jian Li"
    },
    {
      "affs": [
        0
      ],
      "name": "Huan Zhang"
    },
    {
      "affs": [
        0
      ],
      "name": "Xue Chen"
    },
    {
      "affs": [
        0
      ],
      "name": "Jialiang Gao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/56080jx07qjzk.bib",
  "cited_by": 0,
  "doi": "10.3389/fimmu.2026.1959480",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13672005/?tool=EBI",
  "id": "56080jx07qjzk",
  "issns": [
    "1664-3224"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13672005",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2720|Blood groups and transfusion"
    ]
  ],
  "openalex": "W7215073960",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13672005/pdf/?tool=EBI",
  "pmcid": "PMC13672005",
  "pmid": null,
  "published": "2026-10-02",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/56080jx07qjzk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:18Z",
      "native_id": "PMC:PMC13672005",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13672005"
    },
    {
      "first_seen": "2026-10-30T12:19:15Z",
      "native_id": "10.3389/fimmu.2026.1959480",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1959480/full"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "issn:1664-3224",
      "subfield": "immunology"
    }
  ],
  "title": "Three ABO 3′ splice-site variants including a novel one converge on a common splicing defect to attenuate blood group antigen expression",
  "title_text": "Three ABO 3′ splice-site variants including a novel one converge on a common splicing defect to attenuate blood group antigen expression",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:15Z",
  "url": "https://research.draconitic.com/paper/56080jx07qjzk",
  "venue": "Frontiers in immunology",
  "versions": []
}