A matrix method for calculating recurrence risks of unilocal disorders for genetic counselling

Abstract
A matrix method to calculate conditional likelihoods in a pedigree and use them to determine recurrence risks for unilocal disorders in [human] genetic risks is presented. Different matrices are assigned to individual members of the pedigree and combined into matrix expressions. The method is explained for X-linked recessive conditions and autosomal dominant conditions with incomplete penetrance.