Population Frequencies of Single Nucleotide Polymorphisms (SNPs) in Immuno-Modulatory Genes

Inherited polymorphisms in immuno-modulatory genes may contribute to variations in immune function and genetic susceptibility for complex diseases, including cancer. We report results from a comprehensive study to discover novel single nucleotide polymorphisms (SNPs) and to estimate allelic frequency for both novel and known coding and regulatory region SNPs in genes encoding proteins that have been implicated in the immune response to tumors. We identified 12 novel nucleotide substitution variants and one deletion variant in 17 genes analyzed (TGFβR, β2M, IFNγ, TNFα, TNFαR, LTα, IL-6, IL-12, IL-2, IL-1α, IL-1β, IL-1RN, IL-10, CTLA4, CD40L, Fas and FasL). We determined the frequency of these novel polymorphisms, as well as 17 previously identified polymorphisms, in a control sample of 158 individuals, approximately half of which were Caucasian (n = 74) and half of which were African American (n = 84). Significant differences in allele frequencies were observed between the two racial groups for 13/17 genes tested. These allelic variations maybe associated with alterations in immune function and thus susceptibility to a number of complex disease states such as cancer.