Molelular genetic analysis of Ael variant phenotype of ABO blood group system / 대한수혈학회지

ABSTRACT

BACKGROUND: Since the genes encoding glycosyltransferases synthesizing ABO antigens were cloned and sequenced in 1990, genetic polymorphisms and phenotype-genotype correlations have been reported by several investigators, but the genetic basis remains unclear for many subgroups. The Ael phenotype is one of the important A subgroups having very weak A antigen, and recent studies suggested that different alleles can result in this phenotype. METHODS: Three unrelated Ael subgroup samples from Korean blood donors were studied. Exons 6 and 7 of the ABO gene, 91% of the catalytic active part of the glycosyltransferase, were amplified and subjected to direct sequencing. RESULTS: Only C467T substitution in comparison with the consensus sequence of A gene was found in one Ael sample, but this mutation pattern was very commonly observed in normal A1 phenotype of Orientals. The other two samples had T646A (Phe216Ile) and G681A (silent) substitutions beside C467T substitution, reported first from a Japanese Ael individual. CONCLUSIONS: These results indicate that molecular genetic heterogeneity within the Ael subgroup was also seen.