Affected-sib-pair analysis
= Affected-sib-pair analysis
An affected-sib-pair analysis examines marker <identity by descent> between affected <full siblings>. Without <genetic linkage> to the disease locus, the probabilities of sharing zero, one and two copies are $1/4,1/2,1/4$. Excess sharing supplies evidence for linkage under disease models that preferentially transmit a common risk allele to both siblings.
// Target: biology.bigb