Lewis enzyme (alpha1-3/4 fucosyltransferase) polymorphisms do not explain the Lewis phenotype in the gastric mucosa of a Portuguese population.
The human alpha-1,3/4 fucosyltransferase III (FucT III) catalyses the synthesis of Lewis antigens including Le(b) antigen which is a ligand for Helicobacter pylori adhesion. Several polymorphisms have been described in the FUT3 gene affecting both the transmembrane and catalytic domains, some of which affect the enzyme activity. The aim of the present work was to study the Lewis gene polymorphisms in a Caucasian Portuguese population, with a high rate of H. pylori infection, and to evaluate the implications of mutant enzymes in Le(b) expression in the gastric mucosa. We studied 460 asymptomatic or dyspeptic individuals from northern Portugal. Screening for Lewis gene polymorphisms was performed by SSCP and direct sequencing. Lewis phenotype in gastric mucosa was determined by immunohistochemistry. In 47 individuals with a Lewis negative blood group, we found FUT3 gene polymorphisms that were previously described in other populations: 59T>G, 202T>C, 314C>T, 508G>A and 1067T>A. Among the 47 Lewis negative individuals in blood, only nine were also negative in gastric mucosa, suggesting the existence of another alpha 1-4 fucosyltransferase that is responsible for Le(a) and Le(b) synthesis in gastric mucosa.
Serpa
Jacinta
J
IPATIMUP- Institute of Pathology and Molecular Immunology of the University of Porto, University of Porto, Rua Dr. Roberto Frias s/n, 4200, Porto, Portugal. jserpa@ipatimup.pt
Almeida
Raquel
R
Oliveira
Carla
C
Silva
Filipe Santos
FS
Silva
Elisabete
E
Reis
Celso
C
Le Pendu
Jacques
J
Oliveira
Graça
G
Ribeiro
Luís Manuel Cunha
LM
David
Leonor
L
D005260:Female; D005647:Fucosyltransferases / Q000235:genetics*; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D005838:Genotype; D016481:Helicobacter Infections / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000235:genetics*; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics*; D011174:Portugal
D007983:Lewis Blood Group Antigens; D005647:Fucosyltransferases; C019818:3-galactosyl-N-acetylglucosaminide 4-alpha-L-fucosyltransferase