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dc.contributor.advisorDeng, Hong-Wenen_US
dc.contributor.authorLi, Jingen_US
dc.date.accessioned2014-12-08T22:25:39Z
dc.date.available2014-12-08T22:25:39Z
dc.date.issued2000-08en_US
dc.identifier.urihttp://hdl.handle.net/10504/64799
dc.description.abstractThe transmission disequilibrium test (TDT), originally developed for mapping disease genes, has recently been extended to the identification of quantitative trait loci (QTLs). A general TDT (TDTG) has been developed to test linkage and/or linkage disequilibrium between a QTL and a marker in nuclear families that may be composed of more than one heterozygous parent and multiple children. In the investigation of the statistical properties of the TDTg: 1) background polygenes were not considered, which is not realistic, for most quantitative traits are polygenic, and 2) all family members were randomly ascertained. Using a random sample in this case may have limited power, especially when the heritability is small. Usually only extreme values are of primary clinical interest and extensive records are accumulated. In this study, an analytical method was developed to compute the power of the TDTG under various degrees of contribution of background polygenes to phenotypic variation. It is shown that the power of the TDTG is increased with the effects of polygenes when more than one child is employed. How sampling of parents or children based on their extreme values would affect the power of TDTG was also investigated. Three situations were considered based on the selection of phenotypic values of parents or children: 1) two children, one is of extreme value, the other random; 2) two extremely discordant children; 3) one parent is of extreme value. The study shows that the above selective sampling schemes of family members can enhance the power for QTL identification. The increase in the statistical power is particularly dramatic when /?-7 at the QTL is small or intermediate. Therefore, clinical records of extreme individuals are powerful resources for QTL identification by the TDTG. The accuracy of the analytical methods was validated by computational simulations. The results of this study should be of theoretical significance in generalizing the investigation of the TDTG to biologically plausible situations. They should also be of practical value in how to perform the TDTG efficiently by taking advantage of extensive databases enriched with people of extreme phenotypic values.en_US
dc.language.isoen_USen_US
dc.publisherCreighton Universityen_US
dc.rightsCopyright is retained by the Author. A non-exclusive distribution right is granted to Creighton University and to ProQuest following the publishing model selected above.en_US
dc.subject.meshModels, Geneticen_US
dc.subject.meshQuantitative Trait, Heritableen_US
dc.titleRobustness And Power of a TDT Statistic for Mapping Quantitative Trait Locien_US
dc.typeThesis
dc.rights.holderJing Lien_US
dc.publisher.locationOmaha, Nebraskaen_US
dc.description.noteProQuest Traditional Publishing Optionen_US
dc.description.pagesvii, 72 leavesen_US
dc.contributor.cuauthorLi, Jingen_US
dc.degree.levelMS (Master of Science)en_US
dc.degree.disciplineBiomedical Sciences (graduate program)en_US
dc.degree.nameM.S. in Biomedical Sciencesen_US
dc.degree.grantorGraduate Schoolen_US
dc.degree.committeeMurphy, Richard F.en_US
dc.degree.committeeYee, John A.en_US
dc.degree.committeeJohnson, Mark L.en_US
dc.degree.committeeHaynatzki, Gleb R.en_US


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