A case of Bw39 subtype caused by 562C to T mutation of exon 7 of α -1,3-D-galactosyltransferase gene / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To analyze a sample with ABO subgroup using serological and molecular methods.</p><p><b>METHODS</b>The ABO phenotype of the sample was determined with a tube method, and the activity of glycosyltransferases was determined with an uridine diphosphate galactose transferring method. The ABO gene of the propositus was identified by PCR with sequence-specific primers (PCR-SSP). In addition, exons 6 and 7 of the ABO gene were cloned and sequenced.</p><p><b>RESULTS</b>Neither A nor B antigen was identified in the propositus, despite that its anti-B antibody was found to be attenuated. No activity of α -1, 3-D-galactosyltransferase was detected in the serum. The presence of B and O alleles were confirmed by PCR-SSP, and a novel mutation (562C to T) of the exon 7 was confirmed by sequencing, which has led to an amino acid substitution (Arg to Cys) at position 188. The genotype of the propositus was determined as Bnew/O.</p><p><b>CONCLUSION</b>A novel B allele has been identified, which was named as Bw39 by the Blood Group Antigen Gene Mutation Database (BGMUT).</p>