The relative power of linkage and association studies for the detection of genes involved in hypertension

The relative power of linkage and association studies for the detection of genes involved in hypertension. Hypertension is a common disorder that shows a polygenic mode of inheritance. Attempts to localize genes involved in the disorder have been carried out using both linkage and association tests. The relative merit of these two approaches is reviewed with an assessment of their utility for detecting genes involved in hypertension. Power calculations were carried out following the method of Risch and Merikangas [1], assuming markers were typed across the genome. These show that, if there is a single major locus causing susceptibility, non-parametric linkage strategies using affected sibpairs may well prove very effective. However, if there are a number of genes of small effect, the sample size necessary for linkage studies will be prohibitive and a systematic search for allelic association may be more appropriate. This is due to the dramatic reduction in the excess allele sharing for genes of small effect