Mutation of ABO Gene in Thai Blood Donors with A3 Phenotype
Apiwan Pipatvanichkul MSc*, Parichart Permpikul MD**, Sasijit Vejbaesya MD**, Wimol Chinswangwatanakul MD, PhD*
Affiliation : * Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Transfusion Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
The ABO system is the most important of all blood group systems in transfusion practice. The subgroup gives a weak reaction when treated with anti-A or anti-B. The most common subgroup found in Thai blood donors is subgroup A3, which is characterized by mixed-field agglutination when reacted with anti-A and anti-A,B, was caused by mutation in the ABO gene, especially in the exon 7. In the present study mutation in A3 were charactered in exon 7 of the ABO gene in 10 A3 phenotype Thai blood donors from the National Blood Centre, Thai Red Cross Society by PCR amplification and DNA sequencing. Mutations in exon 7 were identified in the A allele of six cases. In four cases, mutations were detected at positions 646T>A, 681G>A, 771C>T and 829G>A. One case showed a double mutations at positions 467C>T and 745C>T and one case showed a mutation at position 467C>T. Four cases showed wild type exon 7 as A101 allele. These mutations were previously reported in BGMUT database and no novel mutation was identified. These data suggest genetic heterogeneity in A3 phenotype in Thai blood donors.
Keywords : A3 phenotype, Blood group, ABO gene, Genetic mutation
