Definition of LOD score

LOD score: In genetics, a statistical estimate of whether two loci (the sites of genes) are likely to lie near each other on a chromosome and are therefore likely to be inherited together as a package.

LOD stands for logarithm of the odds (to the base 10). A LOD score of three or more is generally taken to indicate that two gene loci are close to each other on the chromosome. (A LOD score of three means the odds are a thousand to one in favor of genetic linkage).