chapter  4
14 Pages

Relatedness

ByJohn S. Buckleton, Jo-Anne Bright, Duncan Taylor

This chapter discusses the evaluation of the joint and conditional probabilities of obtaining various genotypes for two people who are related and the effect of this relatedness on the interpretation process. It considers the effect of linkage on the joint and conditional probabilities for relatives. Because of the expansion in size of modern short tandem repeat multiplexes, more linked loci are involved. The complexity of the analysis and the relatively small differences, there may be temptation to avoid making any correction. Genetic distances are sufficiently large that we would not expect linkage disequilibrium at the population level but are sufficiently small that they will affect match probabilities for some close relatives. The difference in match probabilities decreases as the genetic distance increases between the individuals under consideration.