VARIANCE-COMPONENTS MAJOR LOCUS LIKELIHOOD APPROXIMATION FOR QUANTITATIVE, POLYCHOTOMOUS, AND MULTIVARIATE DATA

Pearson [Philos Trans R Soc Lond [A] 200:1-66, 1903], Mendell and Elst on [Biometrics 30:41-57, 1974], and Rice et al. [Biometrics 35:451-459 , 1979] approximated the likelihood of the multifactorial model on a d ichotomous phenotype by a procedure of successive univariate computati on and conditioning. Hasstedt [Pap: Pedigree Analysis Package, Rev. 3. 1989] and Demenais [Am J Hum Genet 49:773-785, 1991 ] extended the al gorithm to include a major locus. Here I extend the algorithm to polyc hotomous, quantitative, and multivariate phenotypes, add a major locus to the model, and describe and evaluate the accuracy of an approximat ion of the resulting variance components/major locus model. (C) 1993 W iley-Liss, Inc.