Probabilities of a pair of genotypes at a diploid marker locus with n codominant alleles (ijkl = 1,2,…, n)

Combinations of genotypesSimilarity indexProbabilityCoefficient
AiAi-AiAi1P(ii, ii)Embedded Image Embedded Image (1 – Pi)Embedded Image (1 – Embedded Image )
AiAj-AiAj1P(ij, ij)Embedded Image ½PiPj(Pi + Pj – 4PiPj)PiPj(1 – 2PiPj)
AiAi-AiAj3/4P(ii, ij)4Embedded Image Pj2Embedded Image Pj(1 – 2Pi)−4Embedded Image Pj
AiAj-AiAk1/2P(ij, ik)4Embedded Image PjPkPi,PjPk(1 – 4Pi)−4Embedded Image PjPk
AiAi-AjAj0P(ii, jj)Embedded Image Embedded Image Embedded Image
AiAi-AjAk0P(ii, ik)2Embedded Image PjPk−2Embedded Image PjPk−2Embedded Image PjPk
AiAj-AkAl0P(ij, kl)PiPjPkPl−PiPjPkPl−PiPjPkPl