Table 3:

Possible choices of frailty distributions for familial correlation. ϕ(x; k) is the density function of the normal distribution with mean 0 and variance k.

Distribution	Laplace transform $\mathcal{L}(s)$
Gamma	(1 + s/k)−k	k > 0
Lognormal	${\int }_{-\infty }^{\infty }\text{exp}\left(-s{e}^x\right)\varphi (x;k)dx$	k > 0