To eliminate the need for distributional assumptions and to reduce the
computational burden associated with the method of maximum likelihood
, several researchers have proposed using estimating equations techniq
ues for segregation analysis. One concern with the application of this
technique has been that the first and second order moments may not ca
rry sufficient information for identifying all of the parameters in se
gregation models. It is shown that in addition to the marginal means a
nd covariances from nuclear family data, up to the third order product
moments need to be used in estimating equations for identifying all o
f the segregation parameters in a major gene model. A polygenic compon
ent and potentially a common family environment parameter can also be
identified using up to the fourth order moments. Two weighting functio
ns are developed to improve statistical efficiency.