RESUMO
Objective To investigate the molecular structure, gene expression and detecting methods of some new variant alleles at FUT2 locus. Method We examined four new variant alleles at FUT2 locus using PCR, RFLPs, gene recombination, DNA sequencing and techniques related to gene expression. Results Three missense gene mutations which were C664T, G868A and G760A respectively were found in three New Guinea individuals. Absence of the glycosyltransferase activity in all three enzymes coded by above three missense gene mutations were confirmed by gene expression techniques. Nonsense mutation A660T was found in one Chinese Han individuals. Changing of sequence of endonuclease SacI resulted from C664T and A660T can be detected by RFLP method. Weak peaks of variats might be missed if DNA sequencing was used to detect heterozygotes. RFLP method can't be used to determine specific site of variation within identified sequence of endonuclease. Conclusion All three FUT2 genes resulted from three mutations C664T, G868A, and G760A were non-secretor genes. More than two methods must be used for checking results each other when detect DNA sequence polymorphisms.