A Homozygous Nonsense Mutation (428G→A) in the Human Secretor ( FUT2 ) Gene Provides Resistance to Symptomatic Norovirus (GGII) Infections

Noroviruses (formerly Norwalk-like viruses) are a major cause of acute gastroenteritis worldwide and are associated with a significant number of nosocomial and food-borne outbreaks. In this study we show that the human secretor FUT2 gene, which codes for an α(1,2)-fucosyltransferase synthesizing the H-type 1 antigen in saliva and mucosa, is associated with susceptibility to norovirus infections. Allelic polymorphism characterization at nucleotide 428 for symptomatic ( n = 53) and asymptomatic ( n = 62) individuals associated with nosocomial and sporadic norovirus outbreaks revealed that homozygous nonsense mutation (428G→A) in FUT2 segregated with complete resistance for the disease. Of all symptomatic individuals, 49% were homozygous (SeSe) and 51% heterozygous (Sese 428 ) secretors, and none were secretor negative (se 428 se 428 ), in contrast to 20% nonsecretors (se 428 se 428 ) among Swedish blood donors ( n = 104) ( P < 0.0002) and 29% for asymptomatic individuals associated with nosocomial outbreaks ( P < 0.00001). Furthermore, saliva from secretor-positive and symptomatic patients but not from secretor-negative and asymptomatic individuals bound the norovirus strain responsible for that particular outbreak. This is the first report showing that the FUT2 nonsecretor (se 428 se 428 ) genotype is associated with resistance to nosocomial and sporadic outbreaks with norovirus.