variables for father, mother and children, βf, βm and βc are fixed parameters associated with disease prevalence for respective family members. The random effects A, F, C, and E are assumed to be normally distributed with mean zero and a unique variance component for each term. Thus we have variance components σsza2,σbpa2,σszf2,σbpf2,σszc2,σbpc2. The non-shared effect E is normal with mean zero and variance σe2.
