ABO*Ael03/O Genotype with ABO Discrepancy: The First Case in Korea

The Ael subgroup expresses the least amount of A antigens and could only be detected by performing the adsorption-elution test. The frequency of the Ael subgroup is about 0.001% in Koreans, and the Ael02 allele, which originates from A102, is the most frequently identified allele in the Korean population. We report a Korean family with the Ael03 allele identified by molecular genetic analysis. To the best of our knowledge, this is the first such report in Korea to date.

Serologic Variability of the A(var) (784G>A) and Its Property of Different Expression Depending on Co-inherited ABO Allele / 대한수혈학회지

BACKGROUND: A allele, A(var), characterized by a 784G>A polymorphism (Asp262Asn) has been identified only in Korean A(weak)B donors. This study evaluated the serological and genetic characteristics of thirteen samples with newly identified A(var) allele. METHODS: This study examined 10 samples with the A(var) allele including 4 members from a family, who were randomly obtained from blood donors recruited at Gwangju-Chonnam Red Cross Blood Center, and patients at the Chonnam National University Hospital. Routine ABO serologic tests, ABO genotyping using an allele specific polymerase chain reaction (AS-PCR), and the sequencing of exon 6 and 7 of ABO gene were performed on all samples. In addition, sequencing of exon 1~5 of the ABO gene was carried out on two randomly selected samples. RESULTS: The A(var) allele was identified in nine A(weak)B and one O (II-1 of the family study) sample. Eight of these nine individuals showed 1+ agglutination with the monoclonal anti-A reagents on forward typing but one sample showed no agglutination. Weak anti-A was detected in all sera. From the family study, the A(var) allele, which was transmitted from the propositus through her descendant (II-1, II-3 and III-1), produced either the weak A phenotype when inherited with a B allele or the O phenotype when inherited with an O allele. CONCLUSION: A(var) erythrocytes showed different agglutination patterns to anti-A. Different expressions (possible allelic enhancement) were observed depending on the co-inherited ABO alleles from samples with the A(var) allele.

Detection of a Hybrid A int Allele by PCR-RFLP / 대한수혈학회지

No abstract available.

A Case of A1B3 Child from a Group A Mother and a Group B Father: New Group B Allele Arising from 547G>A / 대한수혈학회지

Group B subtype, A1B3, was observed in a 22-year-old blood donors by conventional serologic test. In our family study, his father demonstrated uncomplicated B phenotype and his mother typed as group A. We sequenced exon 6 and 7 of phenotypically A1B3 propositus and his family members by direct sequencing and PCR-based cloning. And we have identified a novel Bvar allele characterized by a 547G>A polymorphism present in propositus and his father. This suggests that the Bvar allele is expressed differently depending on the co-inherited ABO allele.

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

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.

Study on B(A) phenotypes and identification of novel B(A)641 allele in chinese population / 中国输血杂志

C mutation. All 8 samples displayed the B(A) phenotype. Their real genotypes were B(A)/O. Conclusion Three B(A) alleles in the Chinese Han population were detected. Two alleles,B(A)700,B(A)640 were reported previously. One novel allele B(A)641, was first identified in this study.