The fusion allele of the FUT2 (secretor type α(1,2)-fucosyltransferase) gene at a high frequency and a new se ³⁸⁵ allele in a Korean population

The fusion gene (se ^fus ), a nonfunctional allele of the FUT2 [secretor type α(1,2)-fucosyltransferase] gene, was found in Japanese populations with high frequencies (4.8–7.9%). In a study on a Korean population, se ^fus was found at a very low frequency (0.6%), but it has not yet been revealed in any other ethnic population. The aim of the present study was to investigate FUT2 gene polymorphisms in a Korean population and to evaluate their implications in secretor expression in saliva. We investigated the frequency of the FUT2 alleles in a Korean population via polymerase chain reaction with confronting two-pair primers (PCR-CTPP) and restriction fragment length polymorphism (PCR-RFLP). Blood samples were collected from 348 random donors in Bundang Koreans. From a total of 696 alleles examined, the frequency of the se ^fus allele in the Korean population was 10.8%. In addition, the new se ³⁸⁵ allele was found in about 7.2% of the subjects, an unusually frequent occurrence compared to any other population investigated so far. The null alleles of the FUT2 gene are another example of rare alleles occurring with unexpectedly high frequencies in distinct geographic regions or populations.