Approaches to genetic linkage analysis.

Genetic linkage analysis concerns the estimation of genetic distance between two or more genetic loci. In genetic epidemiology, it is predominantly used to identify, or map, a genetic locus that is associated with quantitative trait variation or, in the case of binary or discrete traits, modification of the risk of being affected with a disease or phenotype. Linkage analysis uses a panel of reference genetic markers to track the segregation of genomic segments within families or sets of relatives. Individuals within the families must be measured for the trait, and often the families have been selected because they segregate the phenotype of interest.