Effect of polygenes on Xiong’s transmission disequilibrium test of a QTL in nuclear families with multiple children
✍ Scribed by Hong-Wen Deng; Jing Li; Robert R. Recker
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 112 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0741-0395
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✦ Synopsis
The transmission disequilibrium test (TDT), originally developed for mapping disease genes, has recently been extended to identify quantitative trait loci (QTL). For quantitative traits important for human health, generally multiple QTLs are involved. In the investigation of the statistical properties of the TDT, background polygenes (QTLs other than the QTL under test) generally have not been explicitly considered. The effects of background polygenes on the statistical properties of the TDT are thus largely unknown. Investigation of these effects will provide more realistic analyses of the statistical properties of the TDT under biologically plausible situations, and thus provide more accurate guidelines on the application of the TDT in practice. A general TDT (TDT G ) has been developed to test linkage of a QTL in nuclear families that may be composed of more than one heterozygous parent and multiple children. Using the TDT G as an example, we develop an analytical method to investigate the effects of background polygenes on the power of the TDT. The accuracy of our analytical method is validated by computation simulations. We found that the power of the TDT G is increased with background polygenes when more than one child is employed in nuclear families, and the effect is stronger with more children per family recruited for study. The power of the TDT G increases dramatically when the number of children recruited from each nuclear family increases from one to two or from two to three. The type one error rate is not affected by the presence of background Contract