#<p>A, B and C denote pedigrees ascertained by proband, affected cousin pair and at least one affected sib pair, respectively.</p>§<p>In scenarios 1–8, the proportion of pedigree A (“hypothesized” proportion of DSPs) approximately determined the proportion of discordant sib pairs in the simulated data set.</p><p>*In scenario 10, pedigrees were all ascertained by proband. However, 900 of the 1000 pedigrees had the sibships' size of 2, while the other 100 pedigrees had the size of 3.</p