Identification and pedigree analysis for an A(W)37B subtype due to c.940A>G variant of ABO gene / 中华医学遗传学杂志

OBJECTIVE@#To delineate the serological and molecular profiles of a patient with A(w)37B subtype.@*METHODS@#The ABO bloodtypes of the proband, his wife and daughter were determined with a standard serological method. Their ABO genotypes were determined by sequence-specific primer polymerase chain reaction (PCR-SSP). All exons of the ABO gene were directly sequenced. Exons 6 and 7 of the ABO gene were further analyzed by cloning and sequencing.@*RESULTS@#The red blood cells of the proband showed a weak B phenotype. His serum sample contained weak reactive anti-A antibody, which was defined as A(w)B blood group based on the serological characteristics. The A and B alleles were detected by blood group genotyping. Gene cloning and sequencing have identified a characteristic c.940A>G variant (ABO*AW.37) in exon 7 of the ABO gene, which resulted in substitution of Lysine by Glutamate at position 314. The proband's daughter has inherited the ABO*AW.37 allele.@*CONCLUSION@#The c.940A>G variant in exon 7 of the ABO gene probably underlay the decreased activity of GTA transferase and resulted in the Aw37 phenotype.

Study of a Chinese pedigree carrying a novel variant of α-1, 3-N-acetyl galactosaminyl transferase gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree with a novel ABO subtype.@*METHODS@#The proband and his family members were subjected to serological analysis, and their genotypes were determined by fluorescence PCR and direct sequencing of the coding regions of the ABO gene. Exons 6 to 7 of the ABO gene were also subjected to clone sequencing for haplotype analysis.@*RESULTS@#The proband was determined as an AxB subtype. By fluorescence PCR, he was typed as A/B. Clone sequencing has revealed a insertional mutation c.797_798 insT in exon 7 of the ABO gene, which yielded a novel allele. Pedigree analysis confirmed that the novel ABO*A1.02 allele carried by the proband and his sister was inherited from their father. The c.797_798insT mutation has been submitted to GenBank with an accession number of MK125137.@*CONCLUSION@#The c.797_798insT mutation of exon 7 of the ABO gene probably has led to weakened expression of A antigen.