Parametric and semiparametric methods for mapping quantitative trait loci
Most statistical methods for mapping quantitative trait loci (QTLs) have been extensively developed for normally distributed and completely observed phenotypes. A survival model such as Cox's proportional hazards model, or an accelerated failure time model, is the natural choice for regressing a phenotype onto a maker-type when the primary phenotype belongs to failure time. This study proposes parametric and semiparametric methods based on accelerated failure time models for interval mapping. In the parametric model, the EM algorithm (expectation maximization algorithm) is adopted to estimate regression parameters and search the entire chromosome for QTL. In the semiparametric model, the error distribution is left unspecified, and a rank-based inference is developed for the effect and location of QTL. Simulated data are used to compare the mapping performance of the semiparametric methodology with that of the parametric method, which separately selects the correct and incorrect error distribution. Analytical results reveal that the parametric estimators may be more efficient in determining the effect and location of QTL, but have obvious bias when selecting the incorrect error distribution. In contrast, the semiparametric inference is robust to the error distribution.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Guoqing Diao & D. Y. Lin, 2005. "Semiparametric Methods for Mapping Quantitative Trait Loci with Censored Data," Biometrics, The International Biometric Society, vol. 61(3), pages 789-798, 09.
- Mai Zhou, 2005. "Empirical likelihood analysis of the rank estimator for the censored accelerated failure time model," Biometrika, Biometrika Trust, vol. 92(2), pages 492-498, June.
- Zhezhen Jin, 2003. "Rank-based inference for the accelerated failure time model," Biometrika, Biometrika Trust, vol. 90(2), pages 341-353, June.
- Koenker, Roger W & Bassett, Gilbert, Jr, 1978. "Regression Quantiles," Econometrica, Econometric Society, vol. 46(1), pages 33-50, January.
When requesting a correction, please mention this item's handle: RePEc:eee:csdana:v:53:y:2009:i:5:p:1843-1849. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Zhang, Lei)
If references are entirely missing, you can add them using this form.