SIMULATION STUDIES OF SEGREGATION ANALYSIS - APPLICATION TO 2-LOCUS MODELS

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  • 1 January 1984
    • journal article
    • research article
    • Vol. 36  (1) , 167-176
Abstract
The power of a segregation analysis method (1st proposed by Elandt-Johnson) was tested to distinguish between single-locus and 2-locus models, with and without environmentally caused reduced penetrance. The effect of ascertainment probability on the analysis and at the proband-conditioned ascertainment correction proposed by Cannings and Thompson was examined. The segregation analysis has sufficient power to distinguish between the fully-penetrant double-recessive (RR) model and the fully-penetrant single-locus dominant and recessive models. The method can also distinguish fairly well between the dominant-recessive (DR) and RR models, even when one does not take into account the population prevalence. The method has much less power to distinguish between the fully-penetrant RR model and the single-locus models with reduced penetrance. When environmental penetrance is taken account of in the analysis, the power of the method to distinguish between the 1- and 2-locus models improved substantially. The estimates of ascertainment probability, .pi., were robust, regardless of the model under which the data were generated. The Cannings-Thompson approach to ascertainment correction worked well only when the .pi. used to generate the data was less than 0.1. [This study has applications to humans.].