Kinship Evolution for Genome Prediction and Association Study

Kinship, an essential parameter in population genetics, plays an important role in both genomic prediction and genome-wide association study (GWAS). Based on pedigree, kinship coefficient was originally derived from Wright’s inbreeding coefficient, defined as the probability that an individual’s two alleles are identical by descent (IBD). The kinship coefficient between two individuals is the probability that two alleles, sampled at random from each individual, are IBD. With known genetic markers covering the entire genome, a kinship can be derived to reveal the realized relationship which is different from the pedigree expectation because of things like segregation distortion. A trait specific kinship derived for influential markers is more effective for genomic prediction. However, it must be complementary to the testing markers to gain statistical power in GWAS. Furthermore, kinship between two groups of individuals shows the advantage for both genomic prediction and GWAS to balance phenotyping error and distinguishable genetic difference among individuals.