This is a Phase I proposal to begin development of a comprehensive computer software package for the management, simulation, and analysis using Gibbs sampling, of pedigree data. To this end, pedigree data management and simulation components of the package will be developed and tested. Currently available Gibbs sampling methods of analysis will be assessed, and extensions will be evaluated as to their feasibility for inclusion within the time frame of Phase II. The proposed package will fill a void in the currently available array of programs for the analysis of pedigree data. The goal for the final package, to be completed in Phase II, includes all of the following: combined segregation and linkage analysis, inclusion of environmental covariates, adjustment for censored age at disease onset, gene-environment interactions, ascertainment correction, estimation of allele frequencies and allowance for missing data. In addition to comprehensive analysis capabilities, potential users will enjoy a convenient, easy-to-use interface between the management, analysis, and simulation components of the program.