Sampling strategies for model free linkage analyses of quantitative traits: implications for sib pair studies of reading and spelling disabilities to minimize the total study cost.

One approach to establish linkage is based on allele sharing methods for sib pairs. In recent years the use of selected sib pairs to increase power for mapping quantitative traits in humans has been discussed intensively. In this paper the different basic principles for sib pair sampling proposed in the literature are made evident. Implications for ascertainment schemes of sib pairs to minimize the total study cost in linkage analyses on reading and spelling disabilities are discussed.