Polymorphism of the FUT2 gene in an Argentinean population (Rosario)

VALDEZ V; RACCA A; GARCÍA BORRÁS S; RACCA L; COTORRUELO C; BIONDI C

Macao - Cina

Congreso; XXX Internationa Congress of the ISBT; 2008

International Society of Blood Transfusion

Background: The FUT2 gene, which is responsible for the secretor phenotype, encodes an ƒ¿(1,2)-fucosyltransferase that regulates the expression of the ABH antigens in saliva and mucosal tissues and secretions. The FUT2 gene has a significant polymorphism with typical ethnic specificity. The nonsense mutation 428G¨A is characteristic for the dominating nonsecretor allele in Europeans and appears in about 20% of the Caucasian population. The human secretor gene influences the Lewis phenotype of an individual. The Lewis histo-blood group system comprises two major antigens, Lewis a and Lewis b. The Lewis b antigen is a product of two fucosyltransferases, the (1,3/1,4)-fucosyltransferase encoded by the Lewis gene and an (1,2)fucosyltransferase, product of FUT2 gene, which is not required for synthesis of Lewis a antigen. Aim: To analysis the different FUT2 gene polymorphisms in a population of Rosario. Methods: Peripheral blood samples were obtained of volunteers (n=108). The secretor status was determined in plasma with the hemagglutination inhibition technique. Lewis blood group phenotypes of erythrocytes were determined for hemagglutination tests with anti-Lea y anti-Leb monoclonal antibodies. The genomic DNA was extracted and the samples was analyzed by ASA-PCR technique with specific primers for the G428A allele and for the wild type allele of the FUT2 gene followed by RFLP digestion with a specific enzyme for determine the C571T mutation. The PCR products and digestion products were analyzed in 2-percent agarose gel containing ethidium bromide. Results: The results obtained by serologic and molecular methods showed that the 77-percent of the investigate individuals were secretors. These individuals presented a Lewis blood group phenotype Le(a-b+). The G428A polymorphism had present in homozygous in a 7.5-percent, smaller value to report in the bibliography for the Caucasian population. The C571T mutation was not present. Conclusions: The molecular analysis of the FUT2 gene confirms the genetic diversity of the investigated population. The extensive polymorphism and the ethnic specificity of FUT2 alleles suggest that the FUT2 polymorphism may be a useful tool in understanding the evolution of human populations.