Genetic variation of FUT2 in a Vietnamese population: identification of two novel Se enzyme-inactivating mutations

The human FUT2 gene encodes a secretor-type α(1,2)fucosyltransferase, and many population-specific polymorphisms have been reported in the coding region.Direct sequencing, real-time polymerase chain reaction, and high-resolution melt (HRM) analysis were done to detect single-nucleotide polymorphism (SNPs) and copy number variations (CNVs) in a Vietnamese population. The impacts of two novel mutations on the encoded enzyme were examined by a transient expression study.The major nonfunctional allele in the 294 Vietnamese was se(357,385), whereas no CNV was detected. Two novel SNPs, 818CA (Thr273Asn) and 853GA (Ala285Thr), distributed at low frequency, were shown to remarkably affect the enzyme activity.The allelic polymorphism of FUT2 in Vietnamese is similar to that of other East and Southeast Asian populations. This result may reflect the history and gene flow of this population. In addition, HRM analysis seems to be a simple and effective method for screening rare SNPs of FUT2 in a large number of samples. [Correction statement added after online publication 21-Dec-2011: Thr273Ala has been updated to Thr273Asn throughout.]