Do DZs always share 1/4 of Dominant variance?
for dominance yes (think punnet squares) but this could also be used to model epistatis and then it would be <.25
The expected term is 1/4 (which is why we use 0.25 in the ADE model)- but there is variation around this value.
Just like we have used the estimated proportion of alleles identical by descent across the genome (“pihat”) to model the additive genetic variance in DZ twins, we could also use the estimated proportion of genotypes shared between DZ twins across the genome, to estimate the dominance genetic variance. Power is typically low to estimate V_D.
Check out:
1 Like