Table 1.

Statistics of Interest

Statistic	Definition	Reference
R criterion	Sum of no. of repeats of each parental allele among affected siblings; equivalent to Sobel and Lange's (1996) statistic A and recessive LOD-score statistics with q=.1 and q=.01, computed with penetrance vector (.00, .00, .50) at θ=0	Green and Woodrow (1977)
N criterion	Maximum no. of alleles, among affected siblings, from father, + maximum from mother; equivalent to the parental allele–difference method (Abel et al. 1998)	Green and Woodrow (1977)
Spairs	Sum of pairwise IBD sharing, over all affected pairs in pedigree, measured as the no. of pairs sharing two IBD +  1/2the no. of pairs sharing one IBD; equivalent to Sobel and Lange's (1996) statistic D	Whittemore and Halpern (1994)
Sobel and Lange's statistic C (S+L C)	Entropy of alleles among affecteds	Sobel and Lange (1996)
Robust dominant statistic (Srobdom)	Sum, over founder alleles, of 7cl(i)-1, where cl(i) is the no. of affected siblings in the family who have at least one copy of allele i	McPeek (1999)
Sall	Sum of the nos. of nontrivial permutations of all possible sets consisting of one allele from each affected individual	Whittemore and Halpern (1994)
Sobel and Lange's statistic B (S+L B)	Maximum no. of alleles, among affecteds, that are attributable to any one descent tree	Sobel and Lange (1996)
No. of distinct genotypes (S-#geno)	Counts −1 for each distinct genotype among affected siblings	McPeek (1999)
Feingold and Siegmund's version of Spairs (F+S)	Sum of pairwise IBD sharing, over all affected pairs in pedigree, measured as the no. of pairs sharing two IBD +  1/4times the no. of pairs sharing one IBD	Feingold and Siegmund (1997)
Dominant LOD score with q=.1 [ldom(.1)] and q=.01 [ldom(.01)]	LOD score computed with penetrance vector (.00, .50, .50) at θ=0	Ott (1999)