RESUMO
BACKGROUND: Cis-AB is very rare among caucacians and found relatively often among Korean and Japanese populations. The molecular genetic characteristics of Japanese cis-AB were reported recently. All the Japanese cis-AB analyzed so far had identical polymorphisms. This work was performed to disclose the genetic polymorphisms in Korean cis-AB individuals. METHODS: DNA was extracted from 8 cis-AB Koreans. A and O transferase genes were amplified with GA0IN/GA14 allele-specific primer set, and B and cis-AB genes were amplified with GA0IN/GA13 allele-specific primer set. Restriction enzymes including BstPI, KpnI, BssHII, BsaHI, HapII, AluI, and MvaI were used for PCR-RFLP to find out the coexistence of O gene and to determine the nucleotides at nps 467, 526, 703, and 796. Exon 7 was divided into 2 regions and amplified to perform PCR-SSCP. RESULTS: All of the Korean cis-AB analyzed had identical genetic polymorphisms to those reported on Japanese cis-AB. PCR-RFLP with GA0IN/GA13 showed that all cis-AB samples had the allele with A-specific nucleotides at nps 526,703 and 796, and B-specific nucleotides at np 803. Other genetic polymorphisms showed that all of those with cis-AB allele had T at np 467 (leucine at amino acid position 156). CONCLUSION: Genetics polymorphisms reported on 29 Japanese cis-AB so far and 8 Koreans cis-AB analyzed in this study had identical mutations. This may imply that the cis-AB often found in Korea and Japan have single origin. It is plausible that a group of Korean people immigrated from the southwest part of Korea to the western part of Japan through a sea route in the past.