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BACKGROUND AND OBJECTIVES: Discrepancy between forward and reverse ABO grouping could be due to several reasons including genetic mutations of the alleles encoding group specific transferase. The healthy donors found with weak A antigen were investigated to ascertain the allele responsible for variation. MATERIALS AND METHODS: Standard serological methods were employed using commercial antisera. The molecular sequencing was performed on DNA with enrichment library prep kit and a custom designed overlapping probe panel. Binary alignment mapping files, generated on board the Illumina MiSeq instrument and aligned to the GRCh37/Hg19 reference genome, were uploaded to the QIAGEN CLC genomics workbench software (version. 20) where variant call files were generated and analyzed. RESULTS: Red blood cells (RBCs) of six healthy donors, showing weak mix-field agglutination by anti-A and anti-A, B and plasma with absence or weakly reacting anti-A, were investigated serologically. The RBCs incubated with anti-A yield positive elution and their saliva lacked A but possessed H antigen thereby classifying as a historical known phenotype Aend. Family study on 4 probands showed inheritance of the trait. Molecular studies revealed presence of ABO*A allele carrying rare novel variant referred to as c.106delinsGG in line with HGVS recommendation that was thought to be responsible for the variant of A. CONCLUSION: Six cases serologically defined as A were found to be associated with novel weak allele ABO*A (c.106delinsGG). The Aweak phenotype with the novel allele has not been displayed on International Society of Blood Transfusion database, though c.106delinsGG is listed in the UCSC genome browser under rs782544248. [ABSTRACT FROM AUTHOR]

Background and Objectives: Discrepancy between forward and reverse ABO grouping could be due to several reasons including genetic mutations of the alleles encoding group specific transferase. The healthy donors found with weak A antigen were investigated to ascertain the allele responsible for variation., Materials and Methods: Standard serological methods were employed using commercial antisera. The molecular sequencing was performed on DNA with enrichment library prep kit and a custom designed overlapping probe panel. Binary alignment mapping files, generated on board the Illumina MiSeq instrument and aligned to the GRCh37/Hg19 reference genome, were uploaded to the QIAGEN CLC genomics workbench software (version. 20) where variant call files were generated and analyzed., Results: Red blood cells (RBCs) of six healthy donors, showing weak mix-field agglutination by anti-A and anti-A, B and plasma with absence or weakly reacting anti-A, were investigated serologically. The RBCs incubated with anti-A yield positive elution and their saliva lacked A but possessed H antigen thereby classifying as a historical known phenotype A end . Family study on 4 probands showed inheritance of the trait. Molecular studies revealed presence of ABO * A allele carrying rare novel variant referred to as c.106delinsGG in line with HGVS recommendation that was thought to be responsible for the variant of A., Conclusion: Six cases serologically defined as A weak were found to be associated with novel allele ABO*A (c.106delinsGG). The A weak phenotype with the novel allele has not been displayed on International Society of Blood Transfusion database, though c.106delinsGG is listed in the UCSC genome browser under rs782544248., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Asian Journal of Transfusion Science.)

Hemoglobin Q-India is a very rare alpha-chain structural variant caused by the mutation AAG-->GAG (Asp-->His) in the position of codon 64 of the alpha1 gene. Usually it presents in the heterozygous form with electrophoretic mobility in the position of hemoglobin S (HbS) at alkaline pH along with the double bands of HbA2. High-performance liquid chromatography (HPLC) retention time of 4.76 minutes for this abnormal Hb variant identifies it to be HbQ-India. Only isolated case reports exist in literature to describe this rare entity. On cellulose acetate electrophoresis at alkaline pH, the HbQ band can easily be misinterpreted as HbS or HbD if careful screening of the patient for sickle cell with solubility test or sickling test is not done and the abnormal HbA2 band is overlooked. We report a case and emphasize the importance of careful screening with electrophoresis and HPLC in the diagnosis of this rare condition