Estimation of the Inbreeding Coefficient from Phenotype Frequencies by a Method of Maximum Likelihood Scoring

Abstract

A method for estimating the inbreeding coefficient, a, in man based on random sample of individuals is presented for multiple allele systems. The procedure is based upon a method of maximum likelihood scoring. It turns out that genetic systems like ABO blood groups have singular information matrix at aZ = 0 so that no reliable amount of information can be obtained for the inbreeding coefficient in the vicinity of zero. Codominant systems, on the other hand, afford the information (m 1) N at a = 0, where m is the number of alleles and N the size of sample. However, this method is rather insensitive unless a large number of individuals is collected, or we investigate several polymorphic systems for each subject. Numerical examples are given.