Linkage Disequilibrium Mapping: Theory and Applications

Linkage disequilibrium (LD) is a fundamental population genetics concept which involves the association between variants at different sites (or 'loci') on the genome. LD can be induced by many factors, but one of the most important concerns the introduction of a mutant allele into a population. The individual introducing a mutant allele into a population is likely to have some unique DNA variants at neighboring sites which 'co-segregate' with the mutant as it is transmitted from generation to generation. Such co-segregation phenomena can be used to track segments of DNA harboring disease mutations. In this talk some of the fundamental principles behind the exploitation of LD for mapping disease genes are described. An example of a genome-wide mapping study is given which is one of the first to capitalize LD. Attention is also given to many of the thornier statistical issues association with LD mapping.