Type
Text
Type
Dissertation
Advisor
Nancy R. Mendell | Stephen J. Finch. | Wei Zhu | Derek Gordon.
Date
2011-08-01
Keywords
Statistics
Department
Department of Applied Mathematics and Statistics
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/71691
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
In a genome-wide association study (GWAS) for a longitudinal quantitative trait, the trait is measured at multiple time points. GWAS is the examination of marker loci to identify loci associated with the progression of the quantitative trait. I use two models, a single locus model and a multi locus model, to simulate a longitudinal quantitative trait. I use the growth mixture modeling (GMM) method to assign each member of a sample into one of a small number of trajectory groups. The clinically important trajectory group is the one with fastest progression. The Bayesian posterior probability (BPP) of being in the clinically important group is used as a quantitative trait. I test for association with marker loci. I also use the modal BPP in the association test and perform a case/control association analysis. Finally, I compare these methods with the contingency table method. I evaluate the empirical type I error and empirical power using null simulations and power simulations. The principal results are that: (1) Both the BPP method and modal BPP method maintain the correct type I error rate, but the empirical null rejection rate is increasing less than the nominal rate as the nominal type I error rate increases. (2) Both the BPP and modal BPP methods have very high power to detect the disease locus in the single locus model. (3) Both the BPP and modal BPP methods have significant power to detect the disease loci in the multi locus model. The powers of detecting a specific locus are proportional to minor allele frequency (MAF) of loci. (4) Both the BPP and modal BPP methods are better than the contingency table method with regard to the empirical power and the power of the BPP is essentially equal to the power of the modal BPP.
Recommended Citation
Shen, Tong, "Using Growth Mixture Modeling to identify loci associated with the progression of disease" (2011). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 896.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/896