Studiendesigns zur rekrutierung von geschwisterpaaren für die genetische kartierung quantitativer phänotypen

Study designs and statistical methods for genetic mapping of quantitative traits have been further developed in recent years. In the setting of complex diseases, we motivate the preference of quantitative phenotypes compared with the analysis of the disease status. Advantages of sib pair studies over the use of extended pedigrees are discussed. We give an overview of the different sib pair designs for genetic mapping of quantitative traits. The selection of sib pairs via probands with an extreme phenotypic value from a clinic is discussed in particular. This single proband sib pair design is compared with the random selection of sib pairs and the selective choice of sib pairs where both siblings have extreme phenotypic values on a quantitative trait. Finally, we discuss the determination of the optimal ascertainment scheme.