which compares the likelihood of obtaining a linkage between two loci by chance. A LOD
score of 3.0, which has a point-wise p-value of 1 × 10−4, takes into account themultiple testing in a genome-wide linkage screen and is traditionally considered a significant effect. The LOD score can be used to compute the asymptotic p-value through the chi-squared distribution with one degree of freedom, for example in this case p = ½ ∗ P [χ2
(dof = 1) > (2 ∗ log10) ∗ 3] ≈ 1 × 10−4.