Table 1.
Joint Distribution of Ordered Genotype and IBD-Sharing Configuration for ASPs at a Biallelic Marker Under No Association[Note]
|
Weight |
Pr(go, IBD=i) |
|||||
| Ordered Genotypesgo of IndexCase and Sib | φdom | φrec | φadd | i=0 | i=1 | i=2 |
| AA: | ||||||
| AA | 1 | 1 | 1 | z0p4 | z1p3 | z2p2 |
| Aa | 1 | 1/2 | 3/4 | z02p3q | z1p2q | 0 |
| aa | 1/2 | 1/2 | 1/2 | z0p2q2 | 0 | 0 |
| Aa: | ||||||
| AA | 1 | 1/2 | 3/4 | z02p3q | z1p2q | 0 |
| Aa | 1 | 0 | 1/2 | z04p2q2 | z1pq | z22pq |
| aa | 1/2 | 0 | 1/4 | z02pq3 | z1pq2 | 0 |
| aa: | ||||||
| AA | 1/2 | 1/2 | 1/2 | z0p2q2 | 0 | 0 |
| Aa | 1/2 | 0 | 1/4 | z02pq3 | z1pq2 | 0 |
| aa | 0 | 0 | 0 | z0q4 | z1q3 | z2q2 |
| Total | z0 | z1 | z2 | |||
Note.— We assume a marker at Hardy-Weinberg equilibrium with two alleles, A and a, with frequencies p and q=1-p. zi is the probability that an ASP shares i alleles IBD at the marker locus. φdom is the proportion of sibs carrying allele A, φrec the proportion of sibs homozygous for allele A, and φadd the proportion of allele A among all four alleles in the ASP.