Epistatic interaction of FcγRIIIa polymorphisms and IgG1 allotypes has been observed in HSV-1 infection such that, as a result of enhanced ADCC, the high affinity FcγRIIIa-158V/V genotype was only associated with asymptomatic infection in individuals homozygous for the G1m3 IgG1 allotype (434), typically linked to reduced IgG1 responses against viral infections. This evidence concerns the gene FCGR3A and viral infectious disease.