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Two new FUT2 (fucosyltransferase 2 gene) missense polymorphisms, 739G→A and 839T→C, are partly responsible for non-secretor status in a Caucasian population from Northern Portugal

2004; Portland Press; Volume: 383; Issue: 3 Linguagem: Inglês

10.1042/bj20040803

1470-8728

Jacinta Serpa, Nuno Mendes, Celso A. Reis, Luis F. SANTOS SILVA, Raquel Almeida, Jacques Le Pendu, Leonor David,

Veterinary medicine and infectious diseases

Secretor status is defined by the expression of H type 1 antigen on gastric surface epithelium and external secretions. The H type 1 structure, and other fucosylated carbohydrates (Lea, sialyl-Lea, Leb, Lex, sialyl-Lex and Ley), can serve as ligands for several pathogens, including Helicobacter pylori, and are cancer-associated antigens. Secretor individuals are more susceptible to some bacterial and viral infections of the genito-urinary and digestive tracts. The aim of the present study was to examine FUT2 (fucosyltransferase 2 gene) polymorphisms in a Caucasian population of non-secretor individuals (n=36) from northern Portugal and to evaluate the activity of the mutant FUT2 enzymes. The secretor status was determined by UEAI [Ulex europaeus (gorse) lectin] histochemistry in gastric mucosa, and FUT2 polymorphisms were studied by restriction-fragment-length polymorphism and direct sequencing. The majority of non-secretors (88.9%) were homozygous for 428G→A polymorphism; 5.6% were homozygous for 571C→T and 5.6% were homozygous for two new missense polymorphisms, 739G→A (2.8%) and 839T→C (2.8%). By kinetic studies it was demonstrated that the two new FUT2 mutants (739G→A and 839T→C) are almost inactive and are responsible for some non-secretor cases.