My sister's keeper?: genomic research and the identifiability of siblings

BMC Medical Genomics

Table 1 Sib₂ inference error reduction when Sib₁genotype is known.

Sib₂	Sib₁	Prior Prob.	Posterior Prob.	Error Reduction
AA	AA	p²	p² + pq + 1/4q²	\|p² - [p² + pq + 1/4q²]\|
Aa	AA	2pq	pq + 1/2q²	\|2pq - [pq + 1/2q²]\|
aa	AA	q²	1/4q²	\|q² - [1/4q²]\|
AA	Aa	p²	1/2p² + 1/4pq	\|p² - [1/2p² + 1/4pq]\|
Aa	Aa	2pq	1/2p² + (2/3)^-1pq + 1/2q²	\|2pq - [1/2p² + (2/3)^-1pq + 1/2q²]\|
aa	Aa	q²	1/4pq + 1/2q²	\|q² - [1/4pq + 1/2q²]\|
AA	Aa	p²	1/4p²	\|p² - [1/4p²]\|
Aa	Aa	2pq	1/2p²+pq	\|2pq - [1/2p²+pq]\|
aa	Aa	q²	1/4p² + pq + q²	\|q² - [1/4p² + pq + q²]\|

The error reduction depends only on the allele frequencies, and at all frequencies, the error is reduced, improving the quality of genotypic inference.

ISSN: 1755-8794