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.
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.
Serpa
Jacinta
J
Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465 Porto, Portugal. jserpa@ipatimup.pt
Mendes
Nuno
N
Reis
Celso A
CA
Santos Silva
Luis F
LF
Almeida
Raquel
R
Le Pendu
Jacques
J
David
Leonor
L
D019943:Amino Acid Substitution / Q000235:genetics / Q000502:physiology; D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D019556:COS Cells / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D002522:Chlorocebus aethiops; D005647:Fucosyltransferases / Q000235:genetics* / Q000502:physiology; D005753:Gastric Mucosa / Q000737:chemistry / Q000378:metabolism*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D020125:Mutation, Missense / Q000235:genetics* / Q000502:physiology; D010437:Peptic Ulcer / Q000473:pathology; D010649:Phenylalanine / Q000235:genetics / Q000502:physiology; D037121:Plant Lectins / Q000032:analysis; D011110:Polymorphism, Genetic / Q000235:genetics* / Q000502:physiology; D011174:Portugal / Q000453:epidemiology; D012694:Serine / Q000235:genetics / Q000502:physiology; D014162:Transfection / Q000379:methods; D039762:Ulex / Q000737:chemistry; D044465:White People; D000097631:Galactoside 2-alpha-L-fucosyltransferase
D000943:Antigens, Differentiation; D005647:Fucosyltransferases; D010649:Phenylalanine; D037121:Plant Lectins; D012694:Serine; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C403410:H-type-1 antigen