{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T12:05:54Z","timestamp":1748952354724,"version":"3.40.4"},"reference-count":0,"publisher":"S. Karger AG","issue":"4","license":[{"start":{"date-parts":[[2023,1,1]],"date-time":"2023-01-01T00:00:00Z","timestamp":1672531200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2023,1,1]],"date-time":"2023-01-01T00:00:00Z","timestamp":1672531200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Transfus Med Hemother"],"published-print":{"date-parts":[[2023]]},"abstract":"<jats:p>Introduction: The molecular diagnosis of the A1 blood group is based on the exclusion of ABO gene variants causing blood groups A2, B, or O. A specific genetic marker for the A1 blood group is still missing. Recently, long-read ABO sequencing revealed four sequence variations in intron 1 as promising markers for the ABO*A1 allele. Here, we evaluated the diagnostic values of the 4 variants in blood donors with regular and weak A phenotypes and genotypes. Methods: ABO phenotype data (A, B, AB, or O) were taken from the blood donor files. The ABO genotypes (low resolution) were known from a previous study and included the variants c.261delG, c.802G&gt;A, c.803G&gt;C, and c.1061delC. ABO variant alleles (ABO*AW.06,*AW.08,*AW.09,*AW.13, *AW.30, and *A3.02) were identified in weak A donors by sequencing the ABO exons before. For genotyping of the ABO intron 1 variants rs532436, rs1554760445, rs507666, and rs2519093, we applied TaqMan assays with endpoint fluorescence detection according to a standard protocol. Genotypes of the variants were compared with the ABO phenotype and genotype. Evaluation of diagnostic performance included sensitivity, specificity, positive (PPV), and negative predictive value (NPV). Results: In 1,330 blood donors with regular ABO phenotypes and genotypes, the intron 1 variants were significantly associated with the proposed A1 blood group. In 15 donors, we found discrepancies to the genotype of at least one of the 4 variants. For the diagnosis of the ABO*A1 allele, the variants showed 98.79\u201399.48% sensitivity, 99.66\u201399.81% specificity, 98.80\u201399.31% PPV, and 99.66\u201399.86% NPV. Regarding the A phenotype, the diagnostic values were 99.02\u201399.41% sensitivity, 99.63\u201399.76% specificity, 99.41\u201399.61% PPV, and 99.39\u201399.63% NPV. The *A1 marker allele of all intron 1 variants was also associated with the *AW.06, *AW.13, and *AW.30 variants. Samples with *AW.08, *AW.09, and *A3.02 variants lacked this association. Conclusion: The ABO intron 1 variants revealed significant association with the ABO*A1 allele and the A phenotype. However, the intron 1 genotype does not exclude variant alleles causing weak A phenotypes. With the introduction of reliable tag, single nucleotide variants for the A1, A2, B, and O blood groups and the genotyping instead of phenotyping of the ABO blood group are getting more feasible on a routine basis. <\/jats:p>","DOI":"10.1159\/000528683","type":"journal-article","created":{"date-parts":[[2023,1,18]],"date-time":"2023-01-18T22:00:29Z","timestamp":1674079229000},"page":"263-269","source":"Crossref","is-referenced-by-count":1,"title":["Evaluation of Single Nucleotide Variants in Intron 1 of the ABO Gene as Diagnostic Markers for the A1 Blood Group"],"prefix":"10.1159","volume":"50","author":[{"given":"Peter","family":"Bugert","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabi","family":"Rink","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Harald","family":"Kl\u00fcter","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2023,1,18]]},"container-title":["Transfusion Medicine and Hemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/karger.com\/tmh\/article-pdf\/50\/4\/263\/4009709\/000528683.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/tmh\/article-pdf\/50\/4\/263\/4009709\/000528683.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T15:05:16Z","timestamp":1745420716000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000528683"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023]]},"references-count":0,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,8,9]]},"published-print":{"date-parts":[[2023,8,15]]}},"URL":"https:\/\/doi.org\/10.1159\/000528683","archive":["Portico"],"relation":{},"ISSN":["1660-3796","1660-3818"],"issn-type":[{"type":"print","value":"1660-3796"},{"type":"electronic","value":"1660-3818"}],"subject":[],"published":{"date-parts":[[2023]]}}}