Interaction Between Two Biallelic Loci

The concept of attributable risk for one and two binary exposure factors is reviewed and then extend to two biallelic loci. The concept of synergistic, parallel and two other kinds of joint action beteen the two factors are reviewed. Synergistic, parallel, migmatisation and four other kinds of joint action between the two biallelic loci are defined, and it is shown how to estimate the amounts of actions of each kind. The additive and multiplicative models of no interaction are freshly interpreted in terms of synergistic, parallel and migmatisation action.Only the population with disease genes are concerned. The interactions between two biallelic loci are defined detailed. The joint penetrance and risk is defined. It is shown how to estimate the ten parameters. The additive and multiplicative models of no interaction are freshly interpreted in terms of synergistic, parallel and migmatisation action. Four additive models of no interaction are defined as below,When all of the four models are satisfied, there is statistical additive interaction between the two loci, but it is not sure whether biological interation exists between the two loci. When some or all of the four models are not satisfied, there is biological interation between the two loci definitely, and statistical additive interaction scarcely exists between the two the loci.Two types of multiplicative models of no interactions are denned. One is denned from health, shown as below,When all of the four models are satisfied, there is statistical multiplicative interaction between the two loci, but it is not sure whether biological interation existsbetween the two loci. When some or all of the four models are not satisfied, there is biological interation between the two loci definitely, and statistical multiplicative interaction scarcely exists between the two the loci. Another is defined from disease, shown as below,When all of the four models are satisfied, there is statistical multiplicative interaction between the two loci, but it is not sure whether biological interation exists between the two loci. When some or all of the four models are not satisfied, there is biological interation between the two loci definitely, and statistical multiplicative interaction scarcely exists between the two the loci.