THE UTILITY OF DEVIANT SIB PAIRS IN THE DETECTION OF LINKAGE

A tripartite sampling design was used to help deduce the genetic struc ture of a complex biological system. Univariate and multivariate popul ation parameters were estimated from an age/sex stratified sample of u nrelated individuals. Estimates of familial resemblance between and wi thin continuous variables were obtained from a sample of randomly asce rtained nuclear families. Finally, a sample of highly deviant concorda nt and discordant independent sib pairs facilitated the discovery of m ajor genes through multipoint linkage analysis. No false positive sign als were inferred. The pleiotropic effects of major genes, however, be came obscured when linkage analysis was performed on adjusted quantita tive variables. (C) 1997 Wiley-Liss, Inc.