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

• Published in: Biochemical journal 2004-11, Vol.383 (Pt. 3), p.469-474
• Main Authors: Serpa, Jacinta, Mendes, Nuno, Reis, Celso A, Santos Silva, Luis F, Almeida, Raquel, Le Pendu, Jacques, David, Leonor
• Format: Article
• Language: English
• Subjects: Amino Acid Substitution - genetics; Amino Acid Substitution - physiology; Animals; Antigens, Differentiation - biosynthesis; Cell Line; Chlorocebus aethiops; COS Cells - chemistry; COS Cells - metabolism; Fucosyltransferases - genetics; Fucosyltransferases - physiology; Galactoside 2-alpha-L-fucosyltransferase; Gastric Mucosa - chemistry; Gastric Mucosa - metabolism; Helicobacter pylori; Heterozygote; Homozygote; Humans; Mutation, Missense - genetics; Mutation, Missense - physiology; Peptic Ulcer - pathology; Phenylalanine - genetics; Phenylalanine - physiology; Plant Lectins - analysis; Polymorphism, Genetic - genetics; Polymorphism, Genetic - physiology; Portugal - epidemiology; Serine - genetics; Serine - physiology; Transfection - methods; Ulex - chemistry; Ulex europaeus; White People
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/BJ20040803

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 (Le(a), sialyl-Le(a), Le(b), Le(x), sialyl-Le(x) and Le(y)), 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.