Linkage analysis of genetic analysis workshop 12 simulated data based on affected individuals only

A variety of allele-sharing methods was used to assess linkage to disease f or a whole-genome screen in each of ten replicates from the Genetic Analysi s Workshop 12 simulated data. Analysis of each replicate produced many fals e positive results in addition to a few "true" positives. Conditioning on t he strongest initial linkage and reanalyzing using a variety of conditional methods did not improve the power for detection or help discriminate betwe en true and false positive signals. (C) 2001 Wiley-Liss, Inc.