The Information Contained in Multiple Sibling Pairs
S.E. Hodge
Genet Epidemiology , 1, 109-122 (1984)
Abstract
In a sibship of size s, s(s-1)/2 sib pairs can be formed, but these pairs are
statistically dependent when s greater than 2. This study examines how much independent
information is obtained when all possible pairs are used to evaluate the sharing of genes
identical by descent. A logarithmic measure of information, sum pi* log_2(pi)
[Shannon, 1948], is used. The basic unit of information is the binomial "bit," or the amount of
information in the toss of a fair coin. It is shown that a single independent sib pair contains
1.5 bits. The complete sibship contains a total of 2s-3+(1/2)s-1 bits, or (2s-3+(1/2)s-1)/1.5
pair-equivalents of information. The information is reduced if all sib genotypes do not occur
with equal probability.
Allele-sharing linkage analysis