Composite Statistics for QTL Mapping with Moderately Discordant Sibling Pairs  William F. Forrest, Eleanor Feingold  The American Journal of Human Genetics  Volume 66, Issue 5, Pages 1642-1660 (May 2000) DOI: 10.1086/302897 Copyright © 2000 The American Society of Human Genetics Terms and Conditions

Figure 1 Power curves and scatter plots of the component test statistics over 10,000 replications for the simulation experiment. 1.a–1.1.c refer to the linkage analysis with a population sample of sib pairs. 1.a, power curves when θ=0 for the Haseman-Elston test (- - - - - - - -), the mean IBD test (— — — —) and the composite test (————) over the five sample sizes considered. 1.b and 1.c, paired values for the Haseman-Elston test statistic and the mean IBD test for the cases θ=½ and θ=0, respectively, for a population sample of 200 sib pairs. 2.a–2.c show the corresponding plots for MDSP samples. In 2.b and 2.c, 200 MDSPs are analyzed in each of the 10,000 replications for θ=½ and θ=0, respectively. 3.a and 3.c show the corresponding plots for EDSP samples. In 3.b and 3.c, 100 EDSPs are analyzed in each of the 10,000 replications for θ=½ and θ=0, respectively. The American Journal of Human Genetics 2000 66, 1642-1660DOI: (10.1086/302897) Copyright © 2000 The American Society of Human Genetics Terms and Conditions

Figure 2 LOD scores for the three methods, computed at 1-cM spacing along chromosome 8 for 204 moderately discordant sibling pairs taken from the first 717 (i.e., three replications) GAW10 problem 2A nuclear families. Ascertainment is such that one sib falls into the top 35% of the trait distribution and the other into the bottom 35%. The American Journal of Human Genetics 2000 66, 1642-1660DOI: (10.1086/302897) Copyright © 2000 The American Society of Human Genetics Terms and Conditions

Figure 3 a, bivariate scatter plot of 5,000 trait pairs for simulated sib pairs ascertained at random from the population. The points are well described by a bivariate normal distribution. b, bivariate scatter plot of 5,000 trait pairs for simulated sib pairs ascertained subject to the restriction that one trait fall into the lower 35% of the trait distribution and the other into the upper 35% of the distribution. The points are restricted to two diametrically opposed regions because of the ascertainment scheme and, thus, are not well described by a bivariate normal distribution. The American Journal of Human Genetics 2000 66, 1642-1660DOI: (10.1086/302897) Copyright © 2000 The American Society of Human Genetics Terms and Conditions