Background and objectives: The cis-AB blood group is rare, although relatively common amongst Koreans. The serological characteristics and genetic basis of Korean cis-AB blood donors were investigated.
Materials and methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), designed to detect the cis-AB01 allele, was performed on 194 AB samples which demonstrated weak or unusual expression of either or both of the A or B antigens.
Results and conclusions: Sixty cis-AB01 donors were identified. cis-AB01/O01 or O02 were the most common genotypes (36/60) detected only in A(2)B(3) donors, and cis-AB01/B101 (nine of 60) was the least common genotype identified only in A(2)B donors. Surprisingly cis-AB01/A102 (15/60) was identified in a variety of phenotypes (A(1)B(3), A(1)B(x) or el, A(int)B(3)).